Collections documentation could mention performance of BinaryHeap impl

[Ryman]

I can't seem to find anything similar to the docs outlined here for BinaryHeap so I'm left to assume it aligns with the usual bounds as mentioned on wikipedia. It would be good if that information was available either in the collection overview or in the docs for BinaryHeap itself.

[DevQps]

I hope to create a PR for this somewhere today, adding the performance (big O-notation) characteristics to the collection page.