DOC: add doc string to insert_files_in_dir test

tests/test_file.py

@@ -577,6 +577,11 @@ def test_insert_files_in_dir_with_symlink():
 
 @with_setup(None, teardown)
 def test_insert_files_in_dir():
+    """ test if files in directories can be inserted as symlinks via the
+    InsertFilesInDir flag. This tests also verifies that the job can be
+    executed for the root directory after the child directory and only the new
+    files are being inserted.
+    """
     path = get_config().get("IntegrationTests",
                             "test_files.test_insert_files_in_dir.local") + "testfolder/"
     path_on_server = get_config().get("IntegrationTests",