feat: introduce theming - #51

Draft since there's a conflict with -t flag of active command.

I also want to add some tests.

Thanks for the PR :)
Having a bit of a busy week; will try to take a look at it by the end of the week.

Yes, falling back to HOURS_THEME in the absence of the --theme flag sounds good. If the env var is also not set, we fall back to hours'ss built in theme.

Thanks again for the PR. And apologies for the delay in reviewing it.

Overall, the approach looks solid. I've created a PR to your fork with some tweaks that I think make sense. I've listed the details in that PR's description.

Take a look, and lemme know if anything looks odd or is unclear. Would be great if you could give the new subcommands a spin and generally test out a bunch of workflows.

I enabled "Allow edits by maintainers", feel free to push on this PR directly.

Thanks for your contribution! :)

Was a pleasure working on this repo!

I've been using hours daily at work for the past 3/4 weeks, it's amazing!

I have a couple use-cases that are not fully covered, expect more contributions 😉