Rollup merge of #35863 - matthew-piziak:shl-example, r=steveklabnik
Rollup merge of #35863 - matthew-piziak:shl-example, r=steveklabnik

add evocative examples for `Shl` and `Shr`

r? @steveklabnik

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