ci: fix preview pipeline for changes only in .hugo (#587)

.github/workflows/docs_preview_deploy.yaml

@@ -26,7 +26,7 @@ on:
     paths:
       - 'docs/**'
       - 'github/workflows/docs**'
-      - '.hugo'
+      - '.hugo/**'
 
 jobs:
   preview:
@@ -90,4 +90,4 @@ jobs:
               owner: context.repo.owner,
               repo: context.repo.repo,
               body: "🔎 Preview at https://${{ github.repository_owner }}.github.io/${{ github.event.repository.name }}/previews/PR-${{ github.event.number }}/"
-            })
+            })