Incorporate into nvim-treesitter

[tymcauley]

Hey all, I was able to get tree-sitter-firrtl working locally with neovim, by following the directions here and then setting up the queries manually, following the directions here. However, it'd be great if we could install this plugin more easily for neovim. Would you consider including it in the nvim-treesitter repo? I ask because I don't want to volunteer anyone for open-source maintenance duties (although I can't really tell how much ongoing maintenance/development is required for these parsers). If you're alright with it, I'm happy to add this repo to this issue.

It looks like making a PR to add FIRRTL into nvim-treesitter should be pretty simple, based off of this example.

Thanks for putting this together!