Fix language and license tag names and tags

README.md

@@ -3,10 +3,11 @@ annotations_creators:
 - no-annotation
 language_creators:
 - found
-languages:
-- en,de
-licenses:
-- MIT
+language:
+- en
+- de
+license:
+- mit
 multilinguality:
 - 2 languages
 size_categories: