Use command-preview in nightly

[ObserverOfTime]

Neovim nightly supports inccommand previews in user commands.
See: https://neovim.io/doc/user/map.html#:command-preview

[Vonr]

Yeah it's what initially inspired me to add preview mode but unfortunately align.nvim doesnt use a command to run any functions, and instead uses a (poorly made) custom prompt, which is not usable with that feature as far as i know.

[ObserverOfTime]

Converting the functions to commands with arguments shouldn't be hard.
Implementing the preview handler would probably be the harder part.

[Vonr]

I'll try to look into it but I have taken an internship and don't have nearly as much free time as I would like. For now, if anyone else is interested they can open a pull request to implement it, I'll be more likely to accept it if it doesn't break the current api, though thats unlikely without duplication.

[ObserverOfTime]

You can always merge it in another branch. I might try to implement it myself.

[Vonr]

Yep, that works too, might have to edit the master branch's README to direct people to the new one though.