[Model card] Java Code Summarizer model (#7568)

* Create README.md

* Update model_cards/ncoop57/bart-base-code-summarizer-java-v0/README.md
Co-authored-by: Julien Chaumond <chaumond@gmail.com>

model_cards/ncoop57/bart-base-code-summarizer-java-v0/README.md

+---
+tags:
+- summarization
+
+license: mit
+---
+
+## ncoop57/bart-base-code-summarizer-java-v0