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/unescapeHTML.md

@@ -2,7 +2,7 @@
 
 Unescapes escaped HTML characters.
 
-Use `String.replace()` with a regex that matches the characters that need to be unescaped, using a callback function to replace each escaped character instance with its associated unescaped character using a dictionary (object).
+Use `String.prototype.replace()` with a regex that matches the characters that need to be unescaped, using a callback function to replace each escaped character instance with its associated unescaped character using a dictionary (object).
 
 ```js
 const unescapeHTML = str =>