[#73183568] dropdowns +  [#73270894]buttons-dropdowns

in dropdowns

- [x] last dropdowns pattern (which uses [plugin](http://davidstutz.github.io/bootstrap-multiselect/))
 - this pattern doesn't have the same appearance as those in design comp.
Seems here you are loading two docs CSS files `assets/css/docs.min.css` and `assets/css/docs.css` can we load only one?