Screenshots in Docs don't match current UI

[ajn142]

The screenshots haven't been updated since the UI changed. I couldn't figure out what the Enable Threaded Mode button was supposed to be on mobile. I read the docs but the UI was outdated in the screenshots. I eventually had to #to a desktop and use hover to get the tool tip name.

I'm happy to try PR-ing updated images, but unsure when I'll have the time, so I figured I'd better document with an issue first.