build-docs-from-tests: add Vue syntax highlighting

[DannyS712]

When showing file names, if a file name ends in '.vue' use Vue language highlighting for the examples markdown, instead of JavaScript. No support is added yet for any other language.
Update file-name test case to add vue examples. Requires disabling the fixCodeExamples config option for that test to have the intended Vue output in the docs.
Should be the final change needed to solve #98

[edg2s]

Setting a filename seems like an indirect way of setting the language. I think there should be an explicit language setting. We can still fall back to the filename extension if it isn't set.

[DannyS712]

Setting a filename seems like an indirect way of setting the language. I think there should be an explicit language setting. We can still fall back to the filename extension if it isn't set.

So can we do this, and then as a follow-up add the explicit language setting? I'm not sure how to do follow-ups in github like in gerrit

[edg2s]

I'm not sure how to do follow-ups in github like in gerrit
It's sadly not really designed for it, but you can make a PR that merges the next commit into this branch, then it can be rebased later.