Add support for vue templates

[johnfraney]

Adds the vue filetype to the vim plugin

[wbeyda]

Annoying that I can't use sparkup in .vue files because there is no difference between them and HTML tags.

[jestin]

For what it's worth, I'd find this useful

[wbeyda]

I thought I submitted my PR for this. It was one line in and super easy I remember.

[jestin]

For anyone finding this PR while looking for a solution, here's a simple workaround:

1. cd to the ftplugin directory of the sparkup plugin (will vary, depending on how you installed sparkup)
2. run ln -s html vue

This creates a vue symbolic link to the existing html directory. Now *.vue files will activate the sparkup plugin.

It would still be better if vue files were added by default, as this PR would do.

[wbeyda]

Make a vue.vim file in the ftdetect directory and add this line to it.

+au BufNewFile,BufRead *.vue set filetype=html