Docs: move color utility callouts to start of page (#31135)
Docs: move color utility callouts to start of page (#31135)

* Move color utility callouts to start of page

Hierarchically/structurally, in the position they are currently at, the two callouts seem like they "belong" just to the "background color" section. Moving them to the start makes it clearer that those two callouts relate to everything in the page (both "Color" and "Background color" classes.

* Change heading level

otherwise the assistive technology callout looks like it's hierarchically under the "Dealing with specificity" heading
GerHobbelt/bootstrap,m5o/bootstrap,twbs/bootstrap,m5o/bootstrap,tjkohli/bootstrap,inway/bootstrap,twbs/bootstrap,coliff/bootstrap,GerHobbelt/bootstrap,tjkohli/bootstrap,inway/bootstrap,GerHobbelt/bootstrap,inway/bootstrap,coliff/bootstrap