Correct mistakes in docs

Author: joshdifabio

docs/builders.md

@@ -57,17 +57,17 @@ short.
 ```php
 public function testAnimal()
 {
-  $dog = Animal::builder()->setName("dog")->setNumberOfLegs(4)->build();
+  $dog = Animal::builder()->name("dog")->numberOfLegs(4)->build();
   self::assertEquals("dog", $dog->name());
   self::assertEquals(4, $dog->numberOfLegs());
 
   // You probably don't need to write assertions like these; just illustrating.
   self::assertTrue(
-      Animal::builder()->setName("dog")->setNumberOfLegs(4)->build()->equals($dog));
+      Animal::builder()->name("dog")->numberOfLegs(4)->build()->equals($dog));
   self::assertFalse(
-      Animal::builder()->setName("dog")->setNumberOfLegs(4)->build()->equals($dog));
+      Animal::builder()->name("dog")->numberOfLegs(4)->build()->equals($dog));
   self::assertFalse(
-      Animal::builder()->setName("dog")->setNumberOfLegs(2)->build()->equals($dog));
+      Animal::builder()->name("dog")->numberOfLegs(2)->build()->equals($dog));
 }
 ```
 
@@ -84,4 +84,4 @@ generate](generated-builder-example.md).
 *   ... [specify a **default** value for a property?](builders-howto.md#default)
 *   ... [initialize a builder to the same property values as an **existing**
     value instance](builders-howto.md#to_builder)
-*   ... [**validate** property values?](builders-howto.md#validate)
+*   ... [**validate** property values?](builders-howto.md#validate)