Rollup merge of #37840 - brcooley:patch-1, r=steveklabnik
Rollup merge of #37840 - brcooley:patch-1, r=steveklabnik

Fix grammar error in lifetimes.md

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