chore: add paths for docs action (#2279)

Signed-off-by: zirain <[email protected]>

Author: zirain

.github/workflows/docs.yaml

@@ -4,10 +4,12 @@ on:
     branches:
     - "main"
     - "release/v*"
-    paths-ignore:
-    - "**/*.png"
+    paths:
+    - 'site/**'
   pull_request_target:
     types: [opened, synchronize, reopened]
+    paths:
+    - 'site/**'
 
 jobs:
   docs-lint: