Change location and refactor issue closing pattern documentation

Split into user and administrator docs:

- administration/issue_closing_pattern.md
- user/project/issues/automatic_issue_closing.md

[ci skip]

1 files changed, 3 insertions, 38 deletions

diff --git a/doc/customization/issue_closing.md b/doc/customization/issue_closing.md
index 4620bb2dcde..31164ccd465 100644
--- a/doc/customization/issue_closing.md
+++ b/doc/customization/issue_closing.md
@@ -1,39 +1,4 @@
-# Issue closing pattern
+This document was split into:
 
-When a commit or merge request resolves one or more issues, it is possible to automatically have these issues closed when the commit or merge request lands in the project's default branch.
-
-If a commit message or merge request description contains a sentence matching the regular expression below, all issues referenced from
-the matched text will be closed. This happens when the commit is pushed to a project's default branch, or when a commit or merge request is merged into there.
-
-When not specified, the default `issue_closing_pattern` as shown below will be used:
-
-```bash
-((?:[Cc]los(?:e[sd]?|ing)|[Ff]ix(?:e[sd]|ing)?|[Rr]esolv(?:e[sd]?|ing))(:?) +(?:(?:issues? +)?%{issue_ref}(?:(?:, *| +and +)?)|([A-Z][A-Z0-9_]+-\d+))+)
-```
-
-Here, `%{issue_ref}` is a complex regular expression defined inside GitLab, that matches a reference to a local issue (`#123`), cross-project issue (`group/project#123`) or a link to an issue (`https://gitlab.example.com/group/project/issues/123`).
-
-For example:
-
-```
-git commit -m "Awesome commit message (Fix #20, Fixes #21 and Closes group/otherproject#22). This commit is also related to #17 and fixes #18, #19 and https://gitlab.example.com/group/otherproject/issues/23."
-```
-
-will close `#18`, `#19`, `#20`, and `#21` in the project this commit is pushed to, as well as `#22` and `#23` in group/otherproject. `#17` won't be closed as it does not match the pattern. It also works with multiline commit messages.
-
-Tip: you can test this closing pattern at [http://rubular.com][1]. Use this site
-to test your own patterns.
-Because Rubular doesn't understand `%{issue_ref}`, you can replace this by `#\d+` in testing, which matches only local issue references like `#123`.
-
-## Change the pattern
-
-For Omnibus installs you can change the default pattern in `/etc/gitlab/gitlab.rb`:
-
-```
-issue_closing_pattern: '((?:[Cc]los(?:e[sd]|ing)|[Ff]ix(?:e[sd]|ing)?) +(?:(?:issues? +)?%{issue_ref}(?:(?:, *| +and +)?))+)'
-```
-
-For manual installs you can customize the pattern in [gitlab.yml][0] using the `issue_closing_pattern` key.
-
-[0]: https://gitlab.com/gitlab-org/gitlab-ce/blob/master/config/gitlab.yml.example
-[1]: http://rubular.com/r/Xmbexed1OJ
+- [administration/issue_closing_pattern.md](../administration/issue_closing_pattern.md).
+- [user/project/issues/automatic_issue_closing](../user/project/issues/automatic_issue_closing.md).