feat(parser): add very experimental vue template syntax to html grammar

[dyc3]

Summary

This PR aims to explore how an HTML-ish language, specifically Vue, could be implemented. The ultimate goal is to be able to format and create lint rules for Vue.

I think it makes the most sense to eventually add HtmlParseOptions, and be able to conditionally parse Vue's syntax nodes.

Discussion: #1726

Test Plan

Currently, it's broken. The generated code causes the html parser to not be able to compile anymore for multiple reasons.

The first most obvious problem is how the {{ }} interpolation syntax is handled. The code gen seems to create 2 l_curly_token entries on the struct, which is invalid rust, and also not the right token. It should be l_double_curly_token.

The second problem is that the new syntax nodes aren't getting added to HtmlSyntaxKind. No idea what the source of that would be. Added nodes to html_kinds_src.rs

I've managed to fix all the codegen issues.

[denbezrukov]

Thank you for starting to progress the tasks!

Just to clarify, I thought we wanted to have a separate grammar for each HTML-like language and share the same logic via traits?

[dyc3]

I'm currently just experimenting to see how this approach turns out. I want to get a better feel for some of the parser/codegen gotchas. Tbh, I can't really visualize how the trait based approach would work right now, so I'm attempting to get a better feel for this area of the codebase.