Update README.md

Author: javadev

README.md

@@ -86,6 +86,28 @@ U.jsonToXml("{\"a\":{\"b\":\"data\"}}");
     // <a>
     //   <b>data</b>
     // </a>
+    
+Map<String, Object> value = U.objectBuilder()
+    .add("firstName", "John")
+    .add("lastName", "Smith")
+    .add("age", 25)
+    .add("address", U.arrayBuilder()
+        .add(U.objectBuilder()
+            .add("streetAddress", "21 2nd Street")
+            .add("city", "New York")
+            .add("state", "NY")
+            .add("postalCode", "10021")))
+    .add("phoneNumber", U.arrayBuilder()
+        .add(U.objectBuilder()
+            .add("type", "home")
+            .add("number", "212 555-1234"))
+        .add(U.objectBuilder()
+            .add("type", "fax")
+            .add("number", "646 555-4567")))
+    .build();
+    // {firstName=John, lastName=Smith, age=25, address=[{streetAddress=21 2nd Street,
+    // city=New York, state=NY, postalCode=10021}], phoneNumber=[{type=home, number=212 555-1234},
+    // {type=fax, number=646 555-4567}]}
 ```
 
 In addition to porting Underscore's functionality, Underscore-java includes matching unit tests.