Use idiomatic js

Intentionally used the word `rest` instead of `args` because I felt for this case rest better helps people understand that , rest holds all the args after first arg. If I have used `args` then it partly implies that first is not an arg which is not true

snippets/flip.md

@@ -5,7 +5,7 @@ Flip takes a function as an argument, then makes the first argument the last.
 Return a closure that takes variadic inputs, and splices the last argument to make it the first argument before applying the rest.
 
 ```js
-const flip = fn => (...args) => fn(args.pop(), ...args);
+const flip = fn => (first, ...rest) => fn(...rest, first);
 ```
 
 ```js