workflow#changelog: actually commit changelog

.github/workflows/changelog.yml

@@ -1,15 +1,29 @@
-name: Changelog
+name: CI - Changelog
 
 on:
   push:
-    tags:
-      - '*.*.*'
+    branches: [ core ]
 
 jobs:
-  generate_changelog:
+  changelog_prerelease:
+    name: Update Changelog For Prerelease
     runs-on: ubuntu-latest
     steps:
-      - name: Generate change log
+      - name: Checkout code
+        uses: actions/checkout@v2
+        with:
+          ref: core
+      - name: Update Changelog
         uses: heinrichreimer/github-changelog-generator-action@v2.1.1
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
+          issues: true
+          issuesWoLabels: true
+          pullRequests: true
+          prWoLabels: true
+          unreleased: true
+          addSections: '{"documentation":{"prefix":"**Documentation:**","labels":["documentation"]}}'
+      - uses: stefanzweifel/git-auto-commit-action@v4
+        with:
+          commit_message: Update Changelog for PR
+          file_pattern: CHANGELOG.md