Add canvas rotation, not only zoom and move.

[Anos-17]

Canvas rotation should be added.

it would be much easier to draw when you're allowed to change your canvas rotation just like you can change the rotation of your paper in real life.
This app is great and it is bundled with a lot of things but I feel as if this unique feature would truly set it apart. (although not a completely unique feature still quite rare in low quality drawing apps, however this is not low quality so it deserves this )