Official Docs out of date

[iantheconway]

Hey there, thanks for your library, it seems very useful. I noticed an issue with the docs located at:
https://rjagerman.github.io/shoelace/datasets.html

The section on datasets contains the snippet
`from shoelace.dataset import LtrIterator

iterator = LtrIterator(dataset)`

Which appears to contain an incorrect import statement, as LtrIterator is located in shoelace.iterator.

The Readme.MD contains the correct snippet.

Thanks!