Allow workflows to be manually triggered

.github/workflows/main.yml

@@ -1,5 +1,7 @@
 name: OctoDNS
-on: [pull_request]
+on:
+  pull_request:
+  workflow_dispatch:
 
 jobs:
   config:

.github/workflows/stale.yml

@@ -2,6 +2,8 @@ name: 'Close stale issues and PRs'
 on:
   schedule:
     - cron: '42 4 * * *'
+  workflow_dispatch:
+
 jobs:
   stale:
     runs-on: ubuntu-latest