Vetur: Pug full support

[pedro-gilmora]

• [ x] I have searched through existing issues

Feature Request

I think it would be a good feature to have same support like HTML support for Intellisense, auto-completion, Emmet, folding, linting and all designed services to make Vue + Pug a nice dev environment

[yoyo930021]

https://github.com/vuejs/vetur/issues?q=is%3Aissue+is%3Aopen+pug

We don't have enough time to develop or maintenance pug part.
The PR is welcome. If anyone can help, There will be a lot of improvement.

[johnsoncodehk]

I have a plan for vscode-pug-languageservice and it may helpful, I will do it after finishing the accumulation works, so it will not happen soon.

[qnp]

@yoyo930021 @octref I can work on it.

[jdheeter]

I use PUG+Vue everyday and it would be great to have full Pug support in Vetur. Especially the ability to Intellisense component variables in single file components would be a nice productivity boost.