Well, you'd hope the read-only functions like `every`, `map` etc don't mutate. For the ones that do, it might be a good idea to provide examples of how to acco

Well, you'd hope the read-only functions like `every`, `map` etc don't mutate. For the ones that do, it might be a good idea to provide examples of how to accomplish the same thing but without mutating. For example, show how to use `concat` where you'd use `push`.