Update Google sourcemap resources link

Based on this pen: http://codepen.io/zalog/pen/jyoyoR

In addition to #22011 and #21994

* Remove 'hover' from variable names
* Fix indentation in variables

Re-arranged contextual rows/cells so that example HTML matches example result.

normalize is no longer part of BS

Change 'has no affect' to 'has no effect' in Modal documentation

Add `utilities/flex` to the dedicated grid Sass bundle so folks can take advantage of the utilities for basic flex alignment

Add aria-label to docs search field

Fixes #21560. Pretty sure this wasn't intentional, so should be fine to remove.

Fixes #21699

* rename order utilities to intended class names

* Documentation fixes.