Fix broken doc references

[patowen]

I believe most of these changes are non-controversial, although someone other than me may want to double-check that transfers_submitted and transfers_finished are the right function names to reference, although I don't see what else they could be.

One change I considered making as well was renaming the size parameter in colored_circle to min_radius to match the name of the Circle struct field. When I first used that function, I was a surprised that the size parameter was being ignored, even though it made sense in retrospect. However, I also noticed that many other functions would also need their parameters renamed if I went this route, so this PR only fixes broken references.

[kanerogers]

This looks good to me! Thanks!