docs: Expand contribution section in README

Provide a link to the relevant handbook section and some guidance
for submitting a successful merge request, instead of just throwing
two links at the user.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3122>

diff --git a/README.md b/README.md
index 4f3841b183f54ebe67cfe35cc4dca954b7d77c79..dba27ce0934387270d3c9c9dfec63d77fe76aa58 100644 (file)
--- a/README.md
+++ b/README.md
@@ -77,8 +77,23 @@ When in doubt, it is better to ask before opening an issue.
 
 To contribute, open merge requests at https://gitlab.gnome.org/GNOME/gnome-shell.
 
-Commit messages should follow the [commit message guidelines][commit-messages].
+It can be useful to first look at the [GNOME handbook][mr-handbook].
 
+If a change likely requires discussion beyond code review, it is probably better to
+open an issue first, or follow the process for [feature requests](#feature-requests).
+Otherwise, creating a separate issue is not required.
+
+The following guidelines will help your change to be successfully merged:
+
+ * Keep the change as small as possible. If you can split it into multiple
+   merge requests, please do so.
+ * Use multiple commits. This makes it easier to review and helps to diagnose
+   bugs in the future.
+ * Use clear commit messages following the [conventions][commit-messages].
+ * Pay attention to the CI results. Merge requests cannot be merged until the
+   CI passes.
+
+[mr-handbook]: https://handbook.gnome.org/development/change-submission.html
 [commit-messages]: docs/commit-messages.md
 
 ## License