feature: fix native uncommenting

[folke]

Did you check the docs?

• [X] I have read all the ts-comments.nvim docs

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

Add work-around for https://github.com/neovim/neovim/issues/28872

//const a = 123

With a commenstring = "// %s", this won't uncomment.

Related problem:

--- @param foo

Doesn't uncomment with commentstring = "-- %s"

Solution: allow multiple commentstrings per language, or allow a more expressive lua pattern that gets resolved to a proper commentstring based on the ref_position