added stale.yml definition

Signed-off-by: Brooks Townsend <brooks@cosmonic.com>

.github/stale.yml

@@ -0,0 +1,19 @@
+# Number of days of inactivity before an issue becomes stale
+daysUntilStale: 60
+# Number of days of inactivity before a stale issue is closed
+daysUntilClose: 7
+# Issues with these labels will never be considered stale
+exemptLabels:
+  - pinned # Pinned issues should stick around
+  - security # Security issues need to be resolved
+  - roadmap # Issue is captured on the wasmCloud roadmap and won't be lost
+# 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. If this 
+  has been closed too eagerly, please feel free to tag a maintainer so we can
+  keep working on the issue. Thank you for contributing to wasmCloud!
+# Comment to post when closing a stale issue. Set to `false` to disable
+closeComment: false