Docs: Document the globals in wp_print_plugin_file_tree().

Follow-up to [41851].

Props noruzzaman, huzaifaalmesbah, shailu25, sabernhardt.
See #64224.

git-svn-id: https://develop.svn.wordpress.org/trunk@61591 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-admin/includes/misc.php

@@ -492,6 +492,9 @@ function wp_make_plugin_file_tree( $plugin_editable_files ) {
  * @since 4.9.0
  * @access private
  *
+ * @global string $file   Path to the file being edited.
+ * @global string $plugin Path to the plugin file relative to the plugins directory.
+ *
  * @param array|string $tree  List of file/folder paths, or filename.
  * @param string       $label Name of file or folder to print.
  * @param int          $level The aria-level for the current iteration.