Removed explicit coloring part and made some general changes

See merge request !3

A syntax plugin changing the colors is not a good idea, since there are
many themes out there and none of them would work.

Because of that, I've removed the massive chunk of color-related code
and instead linked the plugin keywords to theme keywords.

I'm not sure if the keywords I used are the correct ones, though, so
that's a thing that might need to be adjusted.

I've changed the indentation of the code to 4 spaces. Previously there
were no indentation at all.

Some newlines were removed as well.

There was a b:current_syntax code missing on the bottom of the syntax
code, so I added it.

Master

See merge request !1

Remove sh Dependency, Update Keywords, & Colors