Add related function for each module. [closes #2932]

flattenDeep.js

@@ -10,6 +10,7 @@ const INFINITY = 1 / 0;
  * @category Array
  * @param {Array} array The array to flatten.
  * @returns {Array} Returns the new flattened array.
+ * @see flatMap, flatMapDeep, flatMapDepth, flatten, flattenDepth
  * @example
  *
  * flattenDeep([1, [2, [3, [4]], 5]]);