Option to Dock Editor Vertically in Customizer

[jakejackson1]

It would be nice to have the option to dock the editor window vertically so it's much easier to write and view longer posts side by side - from left to right it would be: the main customizer sidebar, the editor and finally the live preview. On larger monitors this would take better advantage of the screen real estate too. By making this an optional setting everyone wins.

Props for the really cool plugin!

[westonruter]

Good idea. Also relates to #46.

[jwold]

@jakejackson1 and @westonruter are we essentially talking about something like this?

I cropped some images together to play with the look.

[westonruter]

I think so, yes. However, I'd probably want to hold off on any major changes to the post editing UI because I expect that we'll be moving to incorporate Gutenberg components toward the beginning of next year.