chore(ci): add commit format check

All PRs need to follow the contributing guidelines.

https://github.com/Water-Melon/Melon/blob/master/CONTRIBUTING.md#commit-message-format

.github/workflows/commit-lint.yml

@@ -0,0 +1,20 @@
+name: Verify Commit Format
+
+on:
+  pull_request:
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Run commit linter
+        uses: ahmadnassri/action-commit-lint@c46b910837381d1b39c7b7ede72666d7f3e83222 #v2
+        with:
+          config: conventional
+      - name: Point to contributing guide
+        if: failure()
+        run: |
+          echo "Commit message does not follow the contributing guidelines"
+          echo "  https://github.com/Water-Melon/Melon/blob/master/CONTRIBUTING.md#commit-message-format"
+          exit 1

CONTRIBUTING.md

@@ -125,7 +125,6 @@ The type of your commit indicates what type of change this commit is about. The
 
 - **feat**: A new feature
 - **fix**: A bug fix
-- **hotfix**: An urgent bug fix during a release process
 - **docs**: Changes to the README.md, this file, or other such documents
 - **style**: Changes that do not affect the meaning of the code (white-space trimming, formatting, etc...)
 - **perf**: A code change that significantly improves performance