accept repo dispatches

Author: escherize

.github/workflows/process_docs_changes.yml

@@ -9,12 +9,14 @@ on:
         description: Which `metabase/metabase` branch triggered this workflow
         required: true
         type: string
+  repository_dispatch:
+    types: [docs_update]
 
 jobs:
   build-and-commit:
     runs-on: ubuntu-latest
     env:
-      MAIN_REPO_BRANCH: "${{ github.event.inputs.branch_name }}"
+      MAIN_REPO_BRANCH: "${{ github.event.inputs.branch_name || github.event.client_payload.branch_name }}"
     steps:
       - uses: actions/checkout@v4