Write some docs for ToString
Write some docs for ToString

Part of #29376

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