Adds Monarch Grammar File Generation

[montymxb]

Closes #582 by adding an option to generate a Monarch grammar file. This supplements our existing generation for TextMate grammar files, so we can generate one, both, or neither of them as we choose.

As an example I've updated the statemachine example's langium-config to construct a Monarch grammar, and I've added the resulting file.

Currently I've been comparing the results by using Microsoft's Monarch Editor (playground), and it looks good.

The shows is marked as having quite a few errors in VSCode but the format should be ok when used in a Monaco instance. I haven't tried setting this up directly, but that would be the next step.

[montymxb]

Thanks for the feedback @msujew . Next commit of changes should be up sometime later tomorrow.

[montymxb]

New changes are up 👍

[montymxb]

Last review points added in.