Add cleanup.yml

.github/workflows/cleanup.yml

@@ -0,0 +1,19 @@
+name: Issue cleanup
+on:
+  schedule:
+    - cron: '0 23 14 * *' # At 23:00, 14th day of each month
+jobs:
+  triage_issues:
+    name: Issue triage
+    runs-on: ubuntu-latest
+    steps:
+    - name: Find old issues and mark them stale
+      uses: Krizzu/issue-triage-action@v1.0.0
+      with:
+        ghToken: ${{ secrets.GITHUB_TOKEN }}
+        staleAfter: 30
+        closeAfter: 60
+        staleLabel: "STALE 📺"
+        staleComment: "This issue is %DAYS_OLD% days old, marking as stale! cc: @%AUTHOR%"
+        closeComment: "Issue last updated %DAYS_OLD% days ago! Closing down!"
+        showLogs: true