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/pipeFunctions.md

@@ -2,7 +2,7 @@
 
 Performs left-to-right function composition.
 
-Use `Array.reduce()` with the spread operator (`...`) to perform left-to-right function composition.
+Use `Array.prototype.reduce()` with the spread operator (`...`) to perform left-to-right function composition.
 The first (leftmost) function can accept one or more arguments; the remaining functions must be unary.
 
 ```js