(Not Ready)[#73183568] dropdowns +  [#73270894]buttons-dropdowns

in dropdowns

- [ ] code examples
 -  to display copy-and-paste code snippets, `<button>` element (which is trigger) should be included
 - OTOH, design comp doesn't contain `<button>`.

- [ ] 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.