Add support for mesh *skewing* (simpler than warping)?

[adamkewley]

Estimate: still figuring out the scope of this

0.6.0 is likely to include a comprehensive morphing pipeline, but in the meanwhile, it might be a good idea to hedge our bets by implementing a mesh skewing/twisting algorithm. There are existing codebases/snippets online that do this already.

[adamkewley]

This won't be added in 0.5.0 because the focus of 0.5.0 is entirely on frame definition, rather than warping.

It is better-placed for 0.5.1, if there's time to slide it in before 0.6.0's warping feature push begins.