Breaking this task out from T373711. We need to make browserified version of eslint-plugin-vue to provide the same level of in-browser linting that's enjoyed in other content models.

Vue is essentially three languages in one. It might be a lot of work to get this working, and also to keep its footprint to reasonable size.

This is not deemed a priority at the moment given how little Vue pages are edited on-wiki, but we would like to get it taken care of eventually.