Add the probot-stale bot configuration

.github/stale.yml

@@ -0,0 +1,24 @@
+# Configuration for probot-stale - https://github.com/probot/stale
+
+# Number of days of inactivity before an issue becomes stale
+daysUntilStale: 360
+# Number of days of inactivity before a stale issue is closed
+daysUntilClose: 90
+# Issues with these labels will never be considered stale
+exemptLabels:
+  - bug
+# 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 removing the stale label. Set to `false` to disable
+unmarkComment: false
+# Comment to post when closing a stale issue or Pull Request. Set to `false` to disable
+closeComment: >
+  Closing this issue after a prolonged period of inactivity.
+  Please feel free to create a new issue or re-open it if you need.
+# Limit to only `issues` or `pulls`
+only: issues