Update for new Config options in leftwm

[VuiMuich]

As mentioned in leftwm/leftwm#1086 there are coming new config options for keybinds with this PR and new layouts with leftwm/leftwm#1000.

Those should be reflected by checks in leftwm-config.

Eventually we might want to think of a way, to derive the config from leftwm-core, if that's possible.

[blackdragon2447]

Currently I've been working on and off on a rewrite of the tui on the tuirealm branch (That one should be more maintainable), as soon as that is in a state where I feel that it can be merged into main I'll add missing options and update the internal docs.
As for depending on leftwm-core it should be possible, provided that rustc/cargo optimizes out any dead code. If we do that tho that would probably also bring in lefthk-core since the keybind config is in there and not leftw-core iirc.

[VuiMuich]

No hurries or worries. I just thought it might be worth putting it into an issue to track it and potentially reference if it comes up.