Auto merge of #3608 - phansch:improve_util_docs, r=oli-obk
Auto merge of #3608 - phansch:improve_util_docs, r=oli-obk

Some improvements to util documentation

None

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