Rollup merge of #37314 - tshepang:simple, r=GuillaumeGomez
Rollup merge of #37314 - tshepang:simple, r=GuillaumeGomez

doc: a more simple description of Iterator::nth

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