Workflow to create release after PR merge (#470)

* Workflow to create release after PR merge

* Fix step id

* Only run when pr was targeting main

Author: kflansburg

.github/workflows/create-release.yml

@@ -0,0 +1,35 @@
+on:
+  pull_request:
+    types:
+      - closed
+    branches:
+      - main
+
+name: Create Release
+
+jobs:
+  github-release:
+    name: Github Release
+    if: github.event.pull_request.merged == true && startsWith(github.event.pull_request.head.ref, 'releases/')
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+      - name: Extract version
+        id: extract_version
+        run: |
+          BRANCH="${{ github.event.pull_request.head.ref }}"
+          VERSION=${BRANCH:10}
+          echo "version=$VERSION" >> "$GITHUB_OUTPUT"
+      - name: Create Release
+        id: create_release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} 
+        with:
+          tag_name: v${{ steps.extract_version.outputs.version }}
+          release_name: Release v${{ steps.extract_version.outputs.version }}
+          draft: true
+          prerelease: false
+          generate_release_notes: true
+          commitish: ${{ github.event.pull_request.head.sha }}

.github/workflows/createrelease.yml

@@ -436,12 +436,9 @@ edition = "2021"
 # Releasing
 
 1. [Trigger](https://github.com/cloudflare/workers-rs/actions/workflows/create-release-pr.yml) a workflow to create a release PR.
-1. Review version changes and release notes.
-1. Merge PR.
-
-A GitHub release will be created and crates (`worker-sys`, `worker-macros`, `worker`)
-will be published automatically. 
-
+1. Review version changes and merge PR.
+1. A draft GitHub release will be created. Author release notes and publish when ready.
+1. Crates (`worker-sys`, `worker-macros`, `worker`) will be published automatically. 
 
 # Contributing