Fix `license` metadata

We recently updated the datasets metadata for consistency with other repo types (models & spaces)

Thanks! 🙏

README.md

@@ -5,8 +5,8 @@ annotations_creators:
 - clavel
 - inoid
 language_creators: [crowdsourced]
-languages: [es]
-licenses: [apache-2.0]
+language: [es]
+license: [apache-2.0]
 multilinguality: [monolingual]
 pretty_name: ''
 size_categories: