* [CI] Run stylelint
Perform some basic CSS sanity checking and style enforcement.
I removed vendor prefixed linear-gradient and transform because those are from the IE9 era. With IE11 as a minimum and soon obsolete requirement it doesn't make much sense anymore.
* Remove as-link override
* Don't require newline after comment
* Also apply those newline rules to SCSS
* refine opening/closing braces, allow for single-line