Reduce size of index-vX.json files

Closes #962

This removes spaces after commas and colons by setting the 'separators' parameter for both index-v{1,2}.json and ensures UTF-8 characters are outputted as is and not escaped by setting ensure_ascii=False (default is True) for index-v1.json .

For reference see https://docs.python.org/3.9/library/json.html#json.dump .