Update update_index.yaml with better target

.github/workflows/update_index.yaml

@@ -28,8 +28,8 @@ jobs:
         # Diff HEAD with the previous commit
         $diff = git diff --name-only HEAD^ HEAD
 
-        # Check if a markdown file and only a markdown file in the first recursive layer of the docs/ directory has been added or deleted
-        $SourceDiff = $diff | Where-Object { $_ -match '^docs/' -and $_ -like '*.md' -and $_ -notlike '*/*' }
+        # Check if a markdown file and only a markdown file in the docs/ directory has been added or deleted
+        $SourceDiff = $diff | Where-Object { $_ -match '^docs/' -and $_ -like '*.md' }
         $HasDiff = $SourceDiff.Length -gt 0
 
         # Set the output named "docs_changed"