Fix `license` metadata

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

Thanks! 🙏

README.md

@@ -1,17 +1,17 @@
----
-languages:
-- java
-licenses:
-- mit
-multilinguality:
-- monolingual
-pretty_name: 
-- java-cmpx
-size_categories:
-- unknown
-source_datasets: [] 
-task_categories:
-- text-classification
-task_ids:
-- multi-class-classification
----
+---
+language:
+- java
+license:
+- mit
+multilinguality:
+- monolingual
+pretty_name: 
+- java-cmpx
+size_categories:
+- unknown
+source_datasets: [] 
+task_categories:
+- text-classification
+task_ids:
+- multi-class-classification
+---