[FEATURE] Make it easier to add user-defined themes

[unixorn]

Is your feature request related to a problem? Please describe.

Make it possible to add a user-created theme without having to change the code (like #34 did).

Describe the solution you'd like

Ideally something where files in ~/.lima-xbar/themes or ~/Library/Application\ Support/net.unixorn.lima-xbar/themes can be selected from.

It would be nice if there was a Load Theme command that you could give an URL and a Theme Name and the plugin downloaded the theme and installed it as a file so that users don't have to rummage through ~/Library

Describe alternatives you've considered

Using defaults write to define the various states. This seems way more annoying than dropping a file into a directory or downloading one

[pythoninthegrass]

What about writing functions that get exposed in the UI to select available themes or install new ones from a file?

Was thinking it could be a line item either underneath About... or after the VM listing.

[unixorn]

Functions loaded from a plugin file would be a good solution.

[exculibar]

I think write some config files into ~/.lima-xbar directory is good