Address review comments to add "basic usage" sections to docs.
Address review comments to add "basic usage" sections to docs.

graydon/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,graydon/rust,GBGamer/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,graydon/rust,graydon/rust,aidancully/rust,GBGamer/rust,GBGamer/rust