am 9f7d4f2: am 099403d: AI 147796: Add widget design guidelines to new U

Merge commit '9f7d4f2351bf59e7a77d4377add18ffb511bcc55'

* commit '9f7d4f2351bf59e7a77d4377add18ffb511bcc55':
  AI 147796: Add widget design guidelines to new UI Guidelines area in dev guide.