I should be able to easily insert double-square-brackets into my text

(User Story, Investigate , Priority: High, Test Status: No automated tests yet , Reported By Justin du Coeur, )

Summary: Currently, when I'm editing on mobile (especially on a small screen), inserting double-quotes is a pain, and double-square-brackets is a major PITA. We need shortcuts for this.

Here's an initial, hypothetical design:

When I am editing, a narrow column should slide in from the right. (Maybe just in the Advanced Editor, but maybe anywhere -- certainly we will want it when creating a Page.)
The Large Text editor needs to be sensitive to which "mode" it is currently in, QText or QL. This mainly involves counting square brackets and quotes.
There should be some subtle visual indication of which mode we are currently in. (If we could move away from a plain textarea, we might use different fonts?)
When in QText Mode, the column should show a button with open-double-square-brackets; pressing this button inserts those.
When in any Mode except top-level QText, the column should show a button with double-quotes.
When in non-top-level QL mode, the column should show close-double-square-brackets.
For good measure, the column should always show a Done button (probably a checkmark?), to be able to more easily say you're finished.

The notion here is to make Editing, and particularly Design, more mobile-first. We need to get to the point where designing on a phone isn't so painful.