Suggestion: Guide for Integrating Langium with CodeMirror

[montymxb]

Although we personally enjoy using Monaco, there has been interest in seeing how Langium pairs with other editors. From LangDev back in September, we specifically received questions about Langium's compatibility with other editors such as CodeMirror. I think it would make sense to write up at least an introductory example on how to get the two hooked up and talking via the LSP, but we don't have to go in detail there. Just enough to demonstrate that it does work, and we can expand on it later if there's interest.

It would make sense to integrate one of our existing projects as a simple PoC, such as the statemachine, lox, or minilogo.

[msujew]

Related to #54.

[spoenemann]

We might offer an npm package for this integration, maybe with the same amount of effort as writing a guide.