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/getURLParameters.md

@@ -2,7 +2,7 @@
 
 Returns an object containing the parameters of the current URL.
 
-Use `String.match()` with an appropriate regular expression to get all key-value pairs, `Array.reduce()` to map and combine them into a single object.
+Use `String.match()` with an appropriate regular expression to get all key-value pairs, `Array.prototype.reduce()` to map and combine them into a single object.
 Pass `location.search` as the argument to apply to the current `url`.
 
 ```js