fix nav links to end with / to avoid 301 redirect
Merge pull request #14472 from mrduguo/master

fix nav links to end with / to avoid 301 redirect
mention #14320 in browser bugs
grunt
Document that input groups weren't intended for use with <textarea>s

Refs #14362
Merge pull request #14482 from twbs/doc-14362

Document that input groups weren't intended for use with <textarea>s
Gruntfile.js: Simplify copy task.
Merge pull request #14488 from vsn4ik/gruntfile_copy_task

Gruntfile.js: Simplify copy task.
Update grunt-jscs.
Fixes #14443: Only transition what needs transitioning for thumbnails to avoid Safari/Chrome render bug
Tabs plugin accessability

Added support for aria-expanded toggling via javascript. Added
aria-controls, aria-expanded, aria-labelledby to tabs docs.

Added aria-expanded unit tests for tabs

References issue #13554