Feature Request: Add a word to a dictionary via a code action

[David-Else]

Thanks for this awesome software! It would be great to be able to add a word to a dictionary with a code action to remove ERROR Vale.Spelling.

There is a similar grammar checking project written in Rust that does allow adding words to the dictionary here: https://github.com/elijah-potter/harper/blob/master/harper-ls/README.md. I think it is an essential feature :)