comet-score [other_params] --to_json True doesn't output a json file

[me-manikanta]

🐛 Bug

Passing --to_json as True or true doesn't output any JSON file. Whereas passing any other value creates a file with that name and it has the JSON output as expected.

To Reproduce

• Run comet-score (or comet-compare) with --to_json as True
• Observe that there is no json file created

If the test is failing, please add your test cases to the issue (as a draft PR, or simply paste the code to the issue description here).

Expected behaviour

I think the expected behaviour should be the same for any string, but if it is a boolean and is True we can default the output to file output.json. If you think this is not the expected behaviour, then changing the help text as following will avoid the confusion.