Updated about page screenshots with more colors, updated typography shot, simplified hero screenshot of desktop browser. See #26387.
Built from https://develop.svn.wordpress.org/trunk@26775


git-svn-id: http://core.svn.wordpress.org/trunk@26662 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Core updates for the new color schemes.
 * Update about page, there's now 8.
 * Display them four wide, not three, and ensure adequate spacing.
 * Use a dedicated nonce.
 * Push Light to the front in addition to Default.
 * Use user-profile.js on about.php. A few extra things are initialized but they are harmless.

see #26468, #26387.

Built from https://develop.svn.wordpress.org/trunk@26776


git-svn-id: http://core.svn.wordpress.org/trunk@26663 1a063a9b-81f0-0310-95a4-ce76da25c4cd