Add color help output

[joshka]

Color can make it easier to read the help text - e.g.:

In clap this is configured using clap::builder:Styles

const HELP_STYLES: Styles = Styles::styled()
    .header(AnsiColor::Blue.on_default().bold())
    .usage(AnsiColor::Blue.on_default().bold())
    .literal(AnsiColor::White.on_default())
    .placeholder(AnsiColor::Green.on_default());

#[skip_serializing_none]
#[derive(Debug, Serialize, Parser)]
#[command(author, version, about, styles = HELP_STYLES)]
pub struct Args {
    ...
}

It would be nice to support something similar. I'm happy to work on a PR for this if you're interested in this change.

[cbeck88]

Thanks for the suggestion.

Yeah, I'd like to support this.

So far, I didn't directly expose clap types in the API, but I don't really see a problem with having anstyle types in the API, that crate seems totally stable.

I think if we did a new-type wrapper around the Styles type from clap, we'd probably be able to expose the same API and still not be worried that uprev'ing clap (as our dependency) would break our public API?

And then otherwise we could have a styles argument that's similar to the example you show -- I'm thinking it would be a top-level only feature of a Conf struct?

I think that would be a nice patch -- I haven't thought through all the details but I can't see any problems with the idea. Let me know what you think