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/unflattenObject.md

@@ -2,8 +2,8 @@
 
 Unflatten an object with the paths for keys.
 
-Use `Object.keys(obj)` combined with `Array.reduce()` to convert flattened path node to a leaf node.
-If the value of a key contains a dot delimiter (`.`), use `Array.split('.')`, string transformations and `JSON.parse()` to create an object, then `Object.assign()` to create the leaf node.
+Use `Object.keys(obj)` combined with `Array.prototype.reduce()` to convert flattened path node to a leaf node.
+If the value of a key contains a dot delimiter (`.`), use `Array.prototype.split('.')`, string transformations and `JSON.parse()` to create an object, then `Object.assign()` to create the leaf node.
 Otherwise, add the appropriate key-value pair to the accumulator object.
 
 ```js