Command to display supported LSPs

[andrewbenton]

I would like to have a command that will show the LSPs that crush supports. Currently you can find this list by looking at your config and looking at the config file in https://github.com/charmbracelet/x/blob/main/powernap/pkg/config/lsps.json. Having this command will help users easily find which LSPs are supported. This could also give users info about which commands, filetypes, and root markers are needed to actually start using an LSP in a project.