Create stale.yml

marking issues and PRs as stale after 90 days. not closing either for the time being.

.github/workflows/stale.yml

@@ -0,0 +1,23 @@
+name: Mark stale issues and pull requests
+
+on:
+  schedule:
+  - cron: "30 1 * * *"
+
+jobs:
+  stale:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/stale@v3
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        stale-issue-message: 'This issue is stale because it has been open 90 days with no activity. Remove stale label or comment or this will be closed in X days.'
+        stale-pr-message: 'This PR is stale because it has been open 90 days with no activity. Remove stale label or comment or this will be closed in X days.'
+        close-issue-message: 'This issue was closed because it has been stalled for X days with no activity.'
+        close-pr-message: 'This PR was closed because it has been stalled for X days with no activity.'
+        days-before-issue-stale: 90
+        days-before-pr-stale: 90
+        days-before-issue-close: -1
+        days-before-pr-close: -1