Add dedicated "monkeyocr" library tag

It seems this model isn't compatible with Transformers. So instead let's add "monkeyocr" as a dedicated library to the hub.

We can then track downloads as explained here: https://huggingface.co/docs/hub/models-download-stats

README.md

@@ -1,7 +1,7 @@
 ---
 license: apache-2.0
 pipeline_tag: image-text-to-text
-library_name: transformers
+library_name: monkeyocr
 language:
 - zh
 - en