Integrating to LSP

[wingyplus]

I think we should add lsp-mode integration support to the emacs. Maybe we should provide a minor mode (earthly-lsp I think..) that implement lsp client from lsp-mode. The experiment lsp server might be https://github.com/andrewsykim/earthly-lsp.

Ref to discussion #9 (comment)

[Konubinix]

There is also https://github.com/glehmann/earthlyls now. @glehmann was aware of https://github.com/andrewsykim/earthly-lsp but wanted to create the lsp server in rust.

So far, I can tell he did pretty well. Also, he it still very eager to develop new features.

Also, you actually don't need to do anything to support lsp in this repository. I already added the support for https://github.com/glehmann/earthlyls in lsp-mode. You only need to enable lsp from your earthlfiles and then, you can get this.

instead of this

And goto-reference and find-references as well