This PR aims to do a bit more simplification and improvements to the navbar. It addresses the list of todos from #21460 (closed) as a follow-up to redoing the navs with flexbox.
- Makes the
.navbaruse flex andflex-direction: columnto start for fewer overrides and easier mobile-first styling. - Reorganizes the entire file for a more logical order, plus adds a contents list at the top.
- Removes the need to use
.navon our.navbar-nav. - Removes the
flex-grow: 10that was rather random from.navbar-navand uses.mr-autofor easy spacing of flex items. (This was recently added to our flex utils docs.) - Clarifies some class names and directions in the docs.
- Updates all the examples.