Rm hiding feature gate & add 1 more example
Rm hiding feature gate & add 1 more example

Update order docs for `map`

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