fix(styleguide): fixes #337 #338 #339; builds from LESS files

Went ahead and fixed the other two issues because they were small enough to tackle in one PR. 

I also updated the task to build from the LESS files. This introduces an error with the top nav bar, but I'll open another issue to address that. 
What styles are you thinking about specifically that it would be missing? As far as I can recall, @import is only used for vars.less, mixins.less and flexbox.less, which will all be processed separately.