Auto merge of #3524 - phansch:update_contributing, r=phansch
Auto merge of #3524 - phansch:update_contributing, r=phansch

Small updates to CONTRIBUTING.md

None

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