Add support for Close Stale Issues GitHub Action (#99)

https://github.com/marketplace/actions/close-stale-issues

Signed-off-by: Matt Ray <github@mattray.dev>

Author: mattray

.github/configs/stale.yaml

@@ -0,0 +1,5 @@
+## https://github.com/marketplace/actions/close-stale-issues#recommended-permissions
+# Give stalebot permission to update issues and pull requests
+permissions:
+  issues: write
+  pull-requests: write

.github/workflows/stale.yml

@@ -0,0 +1,19 @@
+name: 'Close stale issues and PRs'
+on:
+  schedule:
+    - cron: '30 1 * * *'
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v8
+        with:
+          stale-issue-message: 'This issue has been marked as stale because it has been open for 180 days with no activity. Please remove the stale label or comment or this issue will be closed in 5 days.'
+          close-issue-message: 'This issue was closed because it has been inactive for 185 days with no activity.'
+          stale-pr-message: 'This pull request has been marked as stale because it has been open for 60 days with no activity. Please remove the stale label or comment or this pull request will be closed in 5 days.'
+          close-pr-message: 'This pull request was closed because it has been inactive for 65 days with no activity.'
+          days-before-issue-stale: 180
+          days-before-issue-close: 5
+          days-before-pr-stale: 60
+          days-before-pr-close: 5