* use descriptive docs btn naming

* rename `btn-bd-yellow` to `btn-bd-download`

* sort state vars

* sort state vars
  * info, warning, danger

* rename btn-bd-purple

* rename `.btn-bd-purple` to `.btn-bd-primary`

* align docs color variables

* generate $bd-purple-light color

* with http://razorltd.github.io/sasscolourfunctioncalculator/

* allow overide of docs variables

Nav Tabs use single variable to style `$nav-tabs-link-hover-border-color` and `$nav-tabs-link-active-border-color` (#24639)

Unintentionally removed in #22703. Fixes #24643.

* converts px valures to rem on tooltip variables

* keep as px to match popover changes

* use `background-color` instead of the shorthand
* use `outline: 0` consistently
* fix transform order
* remove quotes from `SFMono-Regular`