Standardise files with files in chef-cookbooks/repo-management

Signed-off-by: Xorima Bot <xorimabot@avon-lea.co.uk>

.github/workflows/branchcleanup.yml

@@ -0,0 +1,17 @@
+---
+name: Branch Cleanup
+# This workflow is triggered on all closed pull requests.
+# However the script does not do anything it a merge was not performed.
+on:
+  pull_request:
+    types: [closed]
+
+env:
+  NO_BRANCH_DELETED_EXIT_CODE: 0
+  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: jessfraz/branch-cleanup-action@master