feat!: use process.stderr stream for warn and error logs

[r0binary]

WHY

• improves error handling because regular output and warning / errors are separated

What Changed

Why

Todo:

• Add tests
• Add docs

Change Type

Indicate the type of change your pull request is:

• documentation
• patch
• minor
• major

[r0binary]

Not sure logging is considered part of the API here. If it isn't then it's surely not a breaking change.

[r0binary]

Some background: What we're looking for is a way to separate logging output from the regular output (auto version in our case). We see log.warn messages on stdout in case of Github API rate limiting, but eventually the proper version gets printed.

This probably changes behavior for many users in a breaking way. So another option is to make the log stream configurable. User could then choose between Stdio or even a file. This is just a proposal (and it misses tests, because it's meant as a discussion starter only at this point). Happy to hear your thoughts.