Add stale bot (#2735)

* Add stale bot

* Update .github/stale.yml

Co-authored-by: Renée Kooi <renee@kooi.me>

Co-authored-by: Renée Kooi <renee@kooi.me>

.github/stale.yml

@@ -0,0 +1,17 @@
+# Number of days of inactivity before an issue becomes stale
+daysUntilStale: 365
+# Number of days of inactivity before a stale issue is closed
+daysUntilClose: 14
+# Issues with these labels will never be considered stale
+exemptLabels:
+  - Keep open
+  - 🔐 Security
+# Label to use when marking an issue as stale
+staleLabel: Stale
+# Comment to post when marking an issue as stale. Set to `false` to disable
+markComment: >
+  This issue has been automatically marked as stale because it has not had
+  recent activity. It will be closed if no further activity occurs. Thank you
+  for your contributions.
+# Comment to post when closing a stale issue. Set to `false` to disable
+closeComment: false