Auto merge of #39778 - ahmedcharles:docs, r=frewsxcv
Auto merge of #39778 - ahmedcharles:docs, r=frewsxcv

Fix some typos in the core::fmt docs.

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