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/unfold.md

@@ -2,7 +2,7 @@
 
 Builds an array, using an iterator function and an initial seed value.
 
-Use a `while` loop and `Array.push()` to call the function repeatedly until it returns `false`.
+Use a `while` loop and `Array.prototype.push()` to call the function repeatedly until it returns `false`.
 The iterator function accepts one argument (`seed`) and must always return an array with two elements ([`value`, `nextSeed`]) or `false` to terminate.
 
 ```js