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/renameKeys.md

@@ -2,7 +2,7 @@
 
 Replaces the names of multiple object keys with the values provided.
 
-Use `Object.keys()` in combination with `Array.reduce()` and the spread operator (`...`) to get the object's keys and rename them according to `keysMap`.
+Use `Object.keys()` in combination with `Array.prototype.reduce()` and the spread operator (`...`) to get the object's keys and rename them according to `keysMap`.
 
 ```js
 const renameKeys = (keysMap, obj) =>