Only dispatch drafts on changes in docs directory (#605)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: mlr

.github/workflows/dispatch-deploy-draft.yml

@@ -5,6 +5,9 @@ on:
   pull_request:
     branches:
       - '**'
+    paths:
+      - 'docs/**'
+      - '.github/workflows/dispatch-deploy-draft.yml'
 
 jobs:
   dispatch-deploy: