Guide: pointers

This is the next section of the guide, and it's on pointers. It's not done yet, as I need to write the section on ownership and borrowing, but I figured I'd share the rest now, to get feedback on the rest of it while I take some time to get that right.
Is the reason for this not being allowed (and for not having two mutable references mentioned in the earlier section) going to be expanded upon in the ownership, lifetime, borrowing section?