GitHub Actions: Add Release Drafter workflow (#4)

Author: tangrufus

.github/workflows/release-drafter.yml

@@ -0,0 +1,20 @@
+name: Release Drafter
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+
+permissions: {}
+
+jobs:
+  update-release-draft:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: read
+    steps:
+      - uses: release-drafter/release-drafter@v6
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}