Update images, fonts, & colors for Witchsky #1

Colors#

• ./src/components/WelcomeModal.tsx (tab/hover selector, all colors)
• ./src/alf/themes.ts (improve contrast, esp. of links)
• ./src/lib/styles.ts (change likes color, remove gradient from new skeet button)
• ./src/style.css (change links color)
• ./src/view/com/util/UserAvatar.tsx (change #0070FF)

Images#

• ./assets/app-icons/ (change new bksy logos to fit Witchsky -remove from social embed!)
• social embed stuff (witchsky logo in image with jollywhoppers logo, use witchsky icon)

Fonts#

Look at the following threads:

• on Bitchsky rebrand ui & logotype
  • Adwaita Sans for ui, Adwaita Mono for logo?
  • Atkinson Hyperlegible for ui, Elms Sans for logo?
• general sans, serif, quoting monospaced