ci: Add gitlint and document commit conventions

* Add gitlint to pre-commit setup
* Update pre-commit setup for installing commit-hooks
* Add "Commit Conventions" contributing docs

Co-authored-by: Cem Aksoylar <caksoylar@users.noreply.github.com>

.pre-commit-config.yaml

@@ -4,7 +4,7 @@ repos:
     rev: v1.5.1
     hooks:
       - id: remove-tabs
-        exclude: "vendor-prefixes\\.txt$"
+        exclude: "vendor-prefixes\\.txt$|.git/COMMIT_EDITMSG"
   - repo: https://github.com/pre-commit/mirrors-clang-format
     rev: v18.1.8
     hooks:
@@ -16,9 +16,14 @@ repos:
     rev: v2.7.1
     hooks:
       - id: prettier
+        exclude: ".git/COMMIT_EDITMSG"
         # Workaround for https://github.com/pre-commit/mirrors-prettier/issues/29
         additional_dependencies:
           - prettier@2.8.7
+  - repo: https://github.com/jorisroovers/gitlint
+    rev: v0.19.1
+    hooks:
+      - id: gitlint
   - repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v4.4.0
     hooks: