(feat): boost expansions doc

https://drive.google.com/drive/u/0/folders/0B1pEbgSGhafkR0ZaZFZFOTdRS0k

here's the boost folder. there are a bunch of docs with useful expansions that we haven't hit yet. need to work on this with Jack Ottman

https://docs.google.com/document/d/1VPYl2D8u3TAQNs883FFIh1cc-VqgTxIhrbPwHX9ivqk/edit