feat: add stale config

.github/stale.yml

+# Configuration for probot-stale - https://github.com/probot/stale
+
+issues:
+  # Number of days of inactivity before an Issue or Pull Request becomes stale
+  daysUntilStale: 7 
+
+  # Number of days of inactivity before an Issue or Pull Request with the stale label is closed.
+  # Set to false to disable. If disabled, issues still need to be closed manually, but will remain marked as stale.
+  daysUntilClose: 7
+
+  # Only issues or pull requests with all of these labels are check if stale. Defaults to `[]` (disabled)
+  onlyLabels:
+    - question
+    - autoclose
+
+  # Issues or Pull Requests with these labels will never be considered stale. Set to `[]` to disable
+  exemptLabels:
+    - p0
+    - bug
+
+  # Comment to post when marking 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.