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/tail.md

@@ -2,7 +2,7 @@
 
 Returns all elements in an array except for the first one.
 
-Return `Array.slice(1)` if the array's `length` is more than `1`, otherwise, return the whole array.
+Return `Array.prototype.slice(1)` if the array's `length` is more than `1`, otherwise, return the whole array.
 
 ```js
 const tail = arr => (arr.length > 1 ? arr.slice(1) : arr);