Add an initial website for Tracker, built using mkdocs

Run `mkdocs` in the toplevel directory to generate the HTML.

The last time Tracker had a website was 2011
(http://web.archive.org/web/20110307070049/http://projects.gnome.org/tracker)
so this is very exciting.

The website is published here:
https://gnome.pages.gitlab.gnome.org/tracker/

The latest API reference documentation is built and included in the
Tracker website, available under the /docs/api-preview/ prefix.
This allows us to browse and reference the documentation during
Tracker 3.0 development, as well as providing a sort of work around
for https://gitlab.gnome.org/GNOME/tracker/-/issues/100.

A warning is added to each documentation page advising that it is
a preview built from Git.

1 files changed, 37 insertions, 0 deletions

diff --git a/.gitlab-ci/checkout-tracker-miners.sh b/.gitlab-ci/checkout-tracker-miners.sh
new file mode 100755
index 000000000..bf1ea0b5b
--- /dev/null
+++ b/.gitlab-ci/checkout-tracker-miners.sh
@@ -0,0 +1,37 @@
+#!/usr/bin/bash
+
+tracker_target=
+
+mkdir extra
+cd extra
+
+git clone https://gitlab.gnome.org/GNOME/tracker-miners.git
+
+if [ $? -ne 0 ]; then
+  echo Checkout failed
+  exit 1
+fi
+
+cd tracker-miners
+
+if [ "$CI_MERGE_REQUEST_TARGET_BRANCH_NAME" ]; then
+  merge_request_remote=${CI_MERGE_REQUEST_SOURCE_PROJECT_URL//tracker/tracker-miners}
+  merge_request_branch=$CI_MERGE_REQUEST_SOURCE_BRANCH_NAME
+
+  echo Looking for $merge_request_branch on remote ...
+  if git fetch -q $merge_request_remote $merge_request_branch 2>/dev/null; then
+    tracker_target=FETCH_HEAD
+  else
+    tracker_target=origin/$CI_MERGE_REQUEST_TARGET_BRANCH_NAME
+    echo Using $tracker_target instead
+  fi
+fi
+
+if [ -z "$tracker_target" ]; then
+  tracker_target=$(git branch -r -l origin/$CI_COMMIT_REF_NAME)
+  tracker_target=${tracker_target:-origin/master}
+  echo Using $tracker_target instead
+fi
+
+git checkout -q $tracker_target
+