Build README

README.md

@@ -10,6 +10,7 @@
 ## Contents
 
 * [Anagrams of string (with duplicates)](#anagrams-of-string-with-duplicates)
+* [Array concatenation](#array-concatenation)
 * [Array difference](#array-difference)
 * [Array intersection](#array-intersection)
 * [Array union](#array-union)
@@ -95,6 +96,15 @@ const anagrams = str => {
 // anagrams('abc') -> ['abc','acb','bac','bca','cab','cba']
 ```
 
+### Array concatenation
+
+Use `Array.concat()` to concatenate and array with any additional arrays and/or values, specified in `args`.
+
+```js
+const ArrayConcat = (arr, ...args) => arr.concat(...args); 
+// ArrayConcat([1], [1, 2, 3, [4]]) -> [1, 2, 3, [4]]
+```
+
 ### Array difference
 
 Create a `Set` from `b`, then use `Array.filter()` on `a` to only keep values not contained in `b`.