[gnome-shell] ci: Add some more commit message rules

[Marge Bot <marge-bot src gnome org>]

commit 15aabdf2879b3b98e2c48146fa562bbe85e5b116
Author: Florian Müllner <fmuellner gnome org>
Date:   Tue Dec 15 18:02:51 2020 +0100

    ci: Add some more commit message rules
    
    Mutter added some additional rules, for instance to enforce proper
    capitalization style in commit messages. That's a good idea, and
    now that adding rules is easy, let's adapt them to gnome-shell.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1544>

 .gitlab-ci/commit-rules.yml | 9 +++++++++
 1 file changed, 9 insertions(+)
---
diff --git a/.gitlab-ci/commit-rules.yml b/.gitlab-ci/commit-rules.yml
index ef7d0805af..9770f45152 100644
--- a/.gitlab-ci/commit-rules.yml
+++ b/.gitlab-ci/commit-rules.yml
@@ -2,3 +2,12 @@ patterns:
   deny:
     - regex: '^$CI_MERGE_REQUEST_PROJECT_URL/(-/)?merge_requests/$CI_MERGE_REQUEST_IID$'
       message: Commit message must not contain a link to its own merge request
+    - regex: '^(st-|St)'
+      message: Commit message subject should not be prefixed with 'st-' or 'St', use 'st/' instead
+      where: subject
+    - regex: '^[^:]+: [a-z]'
+      message: "Commit message subject should be properly Capitalized. E.g. 'window: Marginalize 
extradicity'"
+      where: subject
+    - regex: '^\S*\.(js|c|h):'
+      message: Commit message subject prefix should not include .c, .h etc.
+      where: subject