Add settings option to allow maintaining current tool selection after tool use.

[N-Argyle]

If you draw a shape, after drawing that shape the selected tool resets to your default tool (pointer, hand, etc). This can be frustrating if you intend to draw multiples of the same shape. E.g. drawing multiple lines in a row. You have to reselect the tool each time. Expected behavior for many similar apps is to leave the tool selected, rather than resetting after drawing.

Haven't looked at how tldraw is integrated, but if you want, I am happy to fork and make a PR for this if it's viable.

[Bosmut]

Yeah, great idea! had the same today, while was using this addon