add git-pr-release (#5)

.github/git-pr-release.erb

@@ -0,0 +1,6 @@
+Release <%= Time.now.strftime('%Y-%m-%d %H:%M') %>
+> [!CAUTION]
+> **Create Merge Commit** is recommended to merge this PR.
+<% pull_requests.each do |pr| -%>
+- #<%= pr.number %> <%= pr.mention %>
+<% end -%>

.github/workflows/git-pr-release.yaml

@@ -0,0 +1,24 @@
+name: git-pr-release
+on:
+  push:
+    branches:
+    - develop
+jobs:
+  git-pr-release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0 # git-pr-release needs the git histories
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 3.3
+      - run: gem install --no-document git-pr-release
+      - run: git-pr-release --squashed
+        env:
+          GIT_PR_RELEASE_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GIT_PR_RELEASE_BRANCH_PRODUCTION: main
+          GIT_PR_RELEASE_BRANCH_STAGING: develop
+          GIT_PR_RELEASE_LABELS: release
+          GIT_PR_RELEASE_TEMPLATE: .github/git-pr-release.erb
+          TZ: Asia/Tokyo