Add an Actions workflow to update releases using chandler

Author: althonos

.github/workflows/update-releases.yml

@@ -0,0 +1,21 @@
+name: Update releases
+
+on:
+  - push
+
+jobs:
+  chandler:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v1
+    - name: Set up Ruby 2.7
+      uses: actions/setup-ruby@v1
+      with:
+        ruby-version: 2.7
+    - name: Install chandler gem
+      run: gem install chandler
+    - name: Update releases messages
+      run: chandler push --github="$GITHUB_REPOSITORY" --changelog="CHANGELOG.md"
+      env:
+        CHANDLER_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}