Fixes #11610: Add @grid-float-breakpoint-max to better link navbar behavior across viewports and improve customization.

Also addresses #10371, #10395, and #10465.
Merge branch 'master' of github.com:twbs/bootstrap
Remove redundant, duplicate comment
Merge pull request #11714 from ZDroid/redundant-comment

Remove redundant, duplicate comment
one last grunt
Added links to Ukrainian translation website
Merge pull request #11718 from KostyaTretyak/once

Added link to Ukrainian translation website (in about.html)