Rollup merge of #57746 - mark-i-m:patch-2, r=Centril
Rollup merge of #57746 - mark-i-m:patch-2, r=Centril

Update README.md

Point contributors to the rustc-guide...

r? @steveklabnik

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