feature request: mark missing version number in =foo/bar as "Error"

[jonasstein]

it is a common mistake to write =foo/bar ~amd86 or foo/bar-1.0 ~amd86 in package.keywords

vim syntax highlighting can mark this with the Error color, if a match is defined. I suggest to add these two matches for false syntax in https://github.com/gentoo/gentoo-syntax/blob/master/syntax/gentoo-package-keywords.vim

[msva]

Yeah, nice idea!

I'll try to implement it next time I'll have spare time.