1.3.3

New in this release:

1. Updated JSON metadata format
2. New completions (endpoint, UI): Entering "." after a JSON {"column name"} will give JSON object keys
3. Added more test coverage for queries: Python and SQL in operator
4. Added .keys() and .values()
5. Deprecate .contains(): use item in item instead
6. Fixed bug with .startswith()
7. Optimization for dg.select() (removed unused count query)
8. Don't crash when a HuggingFace dataset can't .take()
9. Added dg.append_columns(dict)