Avoid confusing prototype methods for static methods

Correct: `Array.from()` (it’s a static method)
Incorrect: `Array.join()` (doesn’t exist; it’s a prototype method)

This patch uses the common `#` syntax to denote `.prototype.`.

snippets/takeRightWhile.md

@@ -2,8 +2,8 @@
 
 Removes elements from the end of an array until the passed function returns `true`. Returns the removed elements.
 
-Loop through the array, using a `for...of` loop over `Array.keys()` until the returned value from the function is `true`.
-Return the removed elements, using `Array.reverse()` and `Array.slice()`.
+Loop through the array, using a `for...of` loop over `Array.prototype.keys()` until the returned value from the function is `true`.
+Return the removed elements, using `Array.prototype.reverse()` and `Array.prototype.slice()`.
 
 ```js
 const takeRightWhile = (arr, func) => {