docs: Update the "running GTK apps" section

Style the content a bit better, and use the appropriate links.

1 files changed, 93 insertions, 95 deletions

diff --git a/docs/reference/gtk/running.md b/docs/reference/gtk/running.md
index 2a7ae58389..3a3458eb1d 100644
--- a/docs/reference/gtk/running.md
+++ b/docs/reference/gtk/running.md
@@ -10,70 +10,70 @@ to determine paths to look for certain files. The [X11](#x11-envar),
 [Broadway](#broadway-envar) GDK backends use some additional
 environment variables.
 
-### GTK_DEBUG
+### `GTK_DEBUG`
 
 This variable can be set to a list of debug options, which cause GTK to
 print out different types of debugging information. Some of these options
 are only available when GTK has been configured with `-Ddebug=true`.
 
-actions
+`actions`
 : Actions and menu models
 
-builder
+`builder`
 : GtkBuilder support
 
-geometry
+`geometry`
 : Size allocation
 
-icontheme
+`icontheme`
 : Icon themes
 
-keybindings
+`keybindings`
 : Keybindings
 
-modules
+`modules`
 : Loading of modules
 
-printing
+`printing`
 : Printing support
 
-size-request
+`size-request`
 : Size requests
 
-text
+`text`
 : Text widget internals
 
-tree
+`tree`
 : Tree widget internals
 
 A number of keys are influencing behavior instead of just logging:
 
-interactive
+`interactive`
 : Open the [interactive debugger](#interactive-debugging)
 
-no-css-cache
+`no-css-cache`
 : Bypass caching for CSS style properties
 
-touchscreen
+`touchscreen`
 : Pretend the pointer is a touchscreen device
 
-updates
+`updates`
 : Visual feedback about window updates
 
-resize
+`resize`
 : Highlight resizing widgets
 
-layout
+`layout`
 : Show layout borders
 
-snapshot
+`snapshot`
 : Include debug render nodes in the generated snapshots
 
 The special value `all` can be used to turn on all debug options.
 The special value `help` can be used to obtain a list of all
 supported debug options.
 
-### GTK_PATH
+### `GTK_PATH`
 
 Specifies a list of directories to search when GTK is looking for
 dynamically loaded objects such as input method modules and print
@@ -105,7 +105,7 @@ too, which makes it unsuitable for setting it system-wide (or
 session-wide), since doing so will cause applications using
 different GTK versions to see incompatible modules.
 
-### GTK_IM_MODULE
+### `GTK_IM_MODULE`
 
 Specifies an IM module to use in preference to the one determined
 from the locale. If this isn't set and you are running on the system
@@ -114,7 +114,7 @@ be used for the default IM module. This also can be a colon-separated
 list of input-methods, which GTK will try in turn until it finds one
 available on the system.
 
-### GTK_MEDIA
+### `GTK_MEDIA`
 
 Specifies what backend to load for [class@Gtk.MediaFile]. The possible values
 depend on what options GTK was built with, and can include 'gstreamer',
@@ -122,17 +122,17 @@ depend on what options GTK was built with, and can include 'gstreamer',
 The special value 'help' can be used to obtain a list of all supported
 media backends.
 
-### GTK_EXE_PREFIX
+### `GTK_EXE_PREFIX`
 
 If set, GTK uses `$GTK_EXE_PREFIX/lib` instead of the libdir
 configured when GTK was compiled.
 
-### GTK_DATA_PREFIX
+### `GTK_DATA_PREFIX`
 
 If set, GTK uses `$GTK_DATA_PREFIX` instead of the prefix
 configured when GTK was compiled.
 
-### GTK_THEME
+### `GTK_THEME`
 
 If set, makes GTK use the named theme instead of the theme
 that is specified by the gtk-theme-name setting. This is intended
@@ -145,7 +145,7 @@ The following environment variables are used by GdkPixbuf, GDK or
 Pango, not by GTK itself, but we list them here for completeness
 nevertheless.
 
-### GDK_PIXBUF_MODULE_FILE
+### `GDK_PIXBUF_MODULE_FILE`
 
 Specifies the file listing the GdkPixbuf loader modules to load.
 This environment variable overrides the default value
@@ -155,187 +155,185 @@ specified when GTK was configured, usually `/usr/lib`.)
 The `loaders.cache` file is generated by the
 `gdk-pixbuf-query-loaders` utility.
 
-### GDK_DEBUG
+### `GDK_DEBUG`
 
 This variable can be set to a list of debug options, which cause GDK to
 print out different types of debugging information. Some of these options
 are only available when GTK has been configured with `-Ddebug=true`.
 
-cursor
+`cursor`
 : Information about cursor objects (only win32)
 
-eventloop
-: Information about event loop operation (mostly Quartz)
+`eventloop`
+: Information about event loop operation (mostly macOS)
 
-misc
+`misc`
 : Miscellaneous information
 
-frames
+`frames`
 : Information about the frame clock
 
-settings
+`settings`
 : Information about xsettings
 
-selection
+`selection`
 : Information about selections
 
-clipboard
+`clipboard`
 : Information about clipboards
 
-dnd
+`dnd`
 : Information about drag-and-drop
 
-opengl
+`opengl`
 : Information about OpenGL
 
-vulkan
+`vulkan`
 : Information about Vulkan
 
 A number of options affect behavior instead of logging:
 
-nograbs
+`nograbs`
 : Turn off all pointer and keyboard grabs
 
-gl-disable
+`gl-disable`
 : Disable OpenGL support
 
-gl-software
+`gl-software`
 : Force OpenGL software rendering
 
-gl-texture-rect
+`gl-texture-rect`
 : Use the OpenGL texture rectangle extension, if available
 
-gl-legacy
+`gl-legacy`
 : Use a legacy OpenGL context
 
-gl-gles
+`gl-gles`
 : Use a GLES OpenGL context
 
-vulkan-disable
+`vulkan-disable`
 : Disable Vulkan support
 
-vulkan-validate
+`vulkan-validate`
 : Load the Vulkan validation layer, if available
 
-The special value `all` can be used to turn on all
-debug options. The special value `help` can be used
-to obtain a list of all supported debug options.
+The special value `all` can be used to turn on all debug options. The special
+value `help` can be used to obtain a list of all supported debug options.
 
-### GSK_DEBUG
+### `GSK_DEBUG`
 
 This variable can be set to a list of debug options, which cause GSK to
 print out different types of debugging information. Some of these options
 are only available when GTK has been configured with `-Ddebug=true`.
 
-renderer
+`renderer`
 : General renderer information
 
-cairo
+`cairo`
 : cairo renderer information
 
-opengl
+`opengl`
 : OpenGL renderer information
 
-shaders
+`shaders`
 : Shaders
 
-surface
+`surface`
 : Surfaces
 
-vulkan
+`vulkan`
 : Vulkan renderer information
 
-fallback
+`fallback`
 : Information about fallbacks
 
-glyphcache
+`glyphcache`
 : Information about glyph caching
 
 A number of options affect behavior instead of logging:
 
-diff
+`diff`
 : Show differences
 
-geometry
+`geometry`
 : Show borders
 
-full-redraw
+`full-redraw`
 : Force full redraws for every frame
 
-sync
+`sync`
 : Sync after each frame
 
-vulkan-staging-image
+`vulkan-staging-image`
 : Use a staging image for Vulkan texture upload
 
-vulkan-staging-buffer
+`vulkan-staging-buffer`
 : Use a staging buffer for Vulkan texture upload
 
-The special value `all` can be used to turn on all
-debug options. The special value `help` can be used
-to obtain a list of all supported debug options.
+The special value `all` can be used to turn on all debug options. The special
+value `help` can be used to obtain a list of all supported debug options.
 
-### GDK_BACKEND
+### `GDK_BACKEND`
 
 If set, selects the GDK backend to use. Selecting a backend
 requires that GTK is compiled with support for that backend.
 The following backends can be selected, provided they are
 included in the GDK libraries you are using:
 
-quartz
+`quartz`
 : Selects the native Quartz backend
 
-win32
+`win32`
 : Selects the native backend for Microsoft Windows
 
-x11
+`x11`
 : Selects the native backend for connecting to X11 servers
 
-broadway
+`broadway`
 : Selects the Broadway backend for display in web browsers
 
-wayland
+`wayland`
 : Selects the Wayland backend for connecting to Wayland compositors
 
 This environment variable can contain a comma-separated list of
 backend names, which are tried in order. The list may also contain
-a *, which means: try all remaining backends. The special value
+a `*`, which means: try all remaining backends. The special value
 `help` can be used to make GDK print out a list of all available
 backends. For more information about selecting backends,
-see the [method@Gdk.DisplayManager.get] function.
+see the [func@Gdk.DisplayManager.get] function.
 
-### GDK_VULKAN_DEVICE
+### `GDK_VULKAN_DEVICE`
 
 This variable can be set to the index of a Vulkan device to override
 the default selection of the device that is used for Vulkan rendering.
 The special value `list` can be used to obtain a list of all Vulkan
 devices.
 
-### GSK_RENDERER
+### `GSK_RENDERER`
 
 If set, selects the GSK renderer to use. The following renderers can
 be selected, provided they are included in the GTK library you are
 using and the GDK backend supports them:
 
-help
+`help`
 : Prints information about available options
 
-broadway
+`broadway`
 : Selects the Broadway-backend specific renderer
 
-cairo
+`cairo`
 : Selects the fallback Cairo renderer
 
-gl
+`gl`
 : Selects the default OpenGL renderer
 
-vulkan
+`vulkan`
 : Selects the Vulkan renderer
 
-### GTK_CSD
+### `GTK_CSD`
 
-The default value of this environment variable is 1. If changed
-to 0, this disables the default use of client-side decorations
+The default value of this environment variable is `1`. If changed
+to `0`, this disables the default use of client-side decorations
 on GTK windows, thus making the window manager responsible for
 drawing the decorations of windows that do not have a custom
 titlebar widget.
@@ -344,28 +342,28 @@ CSD is always used for windows with a custom titlebar widget set,
 as the WM should not draw another titlebar or other decorations
 around the custom one.
 
-### GTK_A11Y
+### `GTK_A11Y`
 
 If set, selects the accessibility backend to use. The following
 backends can be selected, provided they are included in the GTK
 library you are using:
 
-help
+`help`
 : Prints information about available options
 
-atspi
+`atspi`
 : Selects the AT-SPI accessibility backend
 
-test
+`test`
 : Selects the test backend
 
-none
+`none`
 : Disables the accessibility backend
 
 The `test` accessibility backend is recommended for test suites and remote
 continuous integration pipelines.
 
-### XDG_DTA_HOME, XDG_DATA_DIRS
+### `XDG_DTA_HOME`, `XDG_DATA_DIRS`
 
 GTK uses these environment variables to locate icon themes
 and MIME information. For more information, see the
@@ -373,14 +371,14 @@ and MIME information. For more information, see the
 the [Shared MIME-Info Database](https://freedesktop.org/Standards/shared-mime-info-spec)
 and the [Base Directory Specification](https://freedesktop.org/Standards/basedir-spec).
 
-### DESKTOP_STARTUP_ID
+### `DESKTOP_STARTUP_ID`
 
 GTK uses this environment variable to provide startup notification
 according to the [Startup Notification Spec](https://standards.freedesktop.org/startup-notification-spec/startup-notification-latest.txt).
 Following the specification, GTK unsets this variable after reading
 it (to keep it from leaking to child processes). So, if you need its
 value for your own purposes, you have to read it before calling
-gtk_init().
+[func@Gtk.init].
 
 ## Interactive debugging
 
@@ -398,9 +396,9 @@ limits what it can do. It is meant as a complement to full-blown
 debuggers and system tracing facilities such as DTrace, not as a
 replacement.
 
-To enable the GTK inspector, you can use the Control-Shift-I or
-Control-Shift-D keyboard shortcuts, or set the `GTK_DEBUG=interactive`
-environment variable.
+To enable the GTK inspector, you can use the <kbd>Control</kbd>+<kbd>Shift</kbd>+<kbd>I</kbd> or
+<kbd>Control</kbd>+<kbd>Shift</kbd>+<kbd>D</kbd> keyboard shortcuts, or
+set the `GTK_DEBUG=interactive` environment variable.
 
 There are a few more environment variables that can be set to influence
 how the inspector renders its UI. `GTK_INSPECTOR_DISPLAY` and