Change stale-bot's label from "wont fix" to the more user friendly "stale".

.github/stale.yml

@@ -4,14 +4,15 @@ daysUntilStale: 60
 daysUntilClose: 7
 # Issues with these labels will never be considered stale
 exemptLabels:
+  - not-stale
   - pinned
   - security
 # Label to use when marking an issue as stale
-staleLabel: wontfix
+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.
+  activity in the past 60 days. It will be closed in seven days 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