All: Use Stale bot to manage stale issues (#2176)

Ref #2127

.github/stale.yml

@@ -0,0 +1,24 @@
+# Number of days of inactivity before an issue becomes stale
+daysUntilStale: 30
+# Number of days of inactivity before a stale issue is closed
+daysUntilClose: 7
+# Issues with these labels will never be considered stale
+exemptLabels:
+  - bug
+  - "help wanted"
+  - "MERGE ME"
+  - "NEEDS REVIEW"
+# Ignore issues in a milestone
+exemptMilestones: true
+# 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/proposal has been automatically marked as idle and stale because it hasn't
+  had any recent activity. It will be automtically closed if no further activity
+  occurs. If you think this is wrong, or the problem still persists, just pop
+  a reply in the comments and one of the maintainers will (try!) to follow up.
+
+  Thank you for contributing :)
+# Comment to post when closing a stale issue. Set to `false` to disable
+closeComment: false