[Docs Update] Make acceptable report formats list more readable

[spalmurray-codecov]

Description

The list of acceptable report formats appears to have been copied from a repo somewhere. It's not terribly readable. Reformat this list.

Page(s)

https://docs.codecov.com/docs/supported-report-formats#exhaustive-acceptable-report-formats

[drazisil-codecov]

@spalmurray-codecov It's a much older version of https://github.com/codecov/worker/blob/13e7e28c23d52f8449ae6282b14d03f9d9552e63/services/report/report_processor.py#L133

I agree it needs cleanup :D