docs: Align CONTRIBUTING.md with develop

main and develop carried different CONTRIBUTING.md blobs after
parallel docs landings. Replace the main copy with the develop tip
content so both branches share one guide.

CONTRIBUTING.md

@@ -1,36 +0,0 @@
-# Contributing
-
-## Pull requests
-
-Prefer pull requests against `develop`. The repository default is `master`
-or `main`; `develop` exists for ongoing integration.
-
-## Commits
-
-Subject form (kernel-style):
-
-    area: Imperative summary
-
-- Imperative mood after the colon (`Add`, `Fix`, `Remove`, …).
-- No trailing period on the subject. Aim for about 75 characters total.
-- Body states the problem and why the change is right.
-- One logical change per commit. Skip the body only when the subject alone
-  is obvious to a reviewer.
-
-## Pull request description
-
-- **What** — what changed
-- **Why** — problem and impact
-- **Test** — concrete steps a reviewer can run
-
-Do not leave the description as “see commits”.
-
-## Issues
-
-Gitea closes issues when a bare issue reference appears in merge text.
-Cite leftover issues by full URL. Only close an issue when the merge
-actually finishes that work.
-
-## License
-
-License: see LICENSE if present; otherwise TBD by owner.