deemphasize immutability and improve swap explanation in pin module
deemphasize immutability and improve swap explanation in pin module

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