Adding stalebot config (#291)

.github/workflows/stale.yml

@@ -0,0 +1,32 @@
+name: 'Close stale issues and PRs'
+on:
+  schedule:
+    - cron: '30 4 * * *'
+permissions:
+  issues: write
+  pull-requests: write
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v8
+        with:
+          # Number of days of inactivity before a stale Issue or Pull Request is closed.
+          # Set to -1 to disable. If disabled, issues still need to be closed manually, but will remain marked as stale.
+          days-before-close: 14
+          # Number of days of inactivity before an Issue or Pull Request becomes stale
+          days-before-stale: 90
+          exempt-issue-labels: no stalebot
+          exempt-pr-labels: no stalebot
+          operations-per-run: 100
+          stale-issue-label: stale
+          stale-pr-label: stale
+          stale-pr-message: >
+            This pull request has been automatically marked as stale because it has not had
+            activity in the last 90 days. It will be closed in 2 weeks if no further activity occurs. Please
+            feel free to give a status update now, ping for review, or re-open when it's ready.
+            Thank you for your contributions!
+          close-pr-message: >
+            This pull request has been automatically closed because it has not had
+            activity in the last 2 weeks. Please feel free to give a status update now, ping for review, or re-open when it's ready.
+            Thank you for your contributions!