Add ANTLR4 language server and editor

[Lotes]

This is cool. I saw this project is built with an ACE editor and a parser in the backend.

I wanted to ask whether you are interested in having editor support (like inline validation, completion etc.) through a language server running in the browser?

There is this open source project called Langium, which can provide a language server derived from a grammar. It is like Xtext for Typescript. It works well with the Monaco editor, which can be used as an LSP client.

I was recently migrating big parts of the Antlr4 grammar to Langium. It still needs some work on it, but when it is ready I could help with creating and integrating the language server and the editor on your site.

WDYT? :)

[parrt]

hi! At this time I think I will hold off on auto completion and everything inside the grammar editor. Ace has a built-in mechanism for that which I will have to explore. Definitely could not understand the Monaco editor so I went with ace haha.

[Lotes]

No problemo, I will come back here when I have more to show ;-).