fix: prevent 'img' directory from being ignored

- Prevent the 'img' directory from being incorrectly ignored.
- This ensures that the 'img' directory is processed correctly,
  fixing an issue where it was excluded unintentionally.

lib/data/doctree/scan.v

@@ -202,7 +202,7 @@ fn is_ignored_dir(path_ Path) !bool {
 		return error('path is not a directory')
 	}
 	name := path.name()
-	return name.starts_with('.') || name.starts_with('_')
+	return name.starts_with('.') || name.starts_with('_') || name == 'img'
 }
 
 // gets collection name from .collection file