maximize canvas preview/minimize code editor

[indefinit]

Would be very nice to have a button to minimize the code editor and maximize the canvas preview if possible. I'm pretty sure codepen has a way to resize panes, right?

[catarak]

I just pushed to production the ability to drag resize the panes (let me know if this is not working) but no way to maximize the editor or the preview. There will also be different views of the sketch, i.e. a presentation view and embed view (see #6).

[shiffman]

Resizing panes is working great!

[catarak]

This feature will be added in the updated design:

[catarak]

this is the same as #208