Add method documentation

lodash/lodash.d.ts

@@ -3458,7 +3458,23 @@ declare module _ {
 	}
 
     //_.mapValues
-    interface LodashStatic {
+    interface LoDashStatic {
+        /**
+         * Creates an object with the same keys as object and values generated by running each own
+         * enumerable property of object through the callback. The callback is bound to thisArg and
+         * invoked with three arguments; (value, key, object).
+         *
+         * If a property name is provided for callback the created "_.pluck" style callback will return
+         * the property value of the given element.
+         *
+         * If an object is provided for callback the created "_.where" style callback will return true
+         * for elements that have the properties of the given object, else false.
+         *
+         * @param object The object to iterate over.
+         * @param callback The function called per iteration.
+         * @param thisArg `this` object in `iterator`, optional.
+         * @return Returns a new object with values of the results of each callback execution.
+         */
         mapValues<Mapped, T>(
             object: any,
             callback: ObjectIterator<any, any>,