Added documentation for doctrine (#142)

This will fix #97 and fix #141

Author: Nyholm

Resources/doc/doctrine.md

@@ -0,0 +1,42 @@
+# Doctrine annotation support
+
+*[<< Back to documentation index](Resources/doc/index.md)*
+
+Wouldn't it be great if you could automatically save the coordinates of a users 
+address every time it is updated? Wait not more here is the feature you been always
+wanted.
+
+``` php
+
+use Bazinga\GeocoderBundle\Mapping\Annotation as Geocoder;
+
+/**
+ * @Geocoder\Geocodable
+ */
+class User
+{
+    /**
+     * @Geocoder\Address
+     */
+    private $address;
+
+    /**
+     * @Geocoder\Latitude
+     */
+    private $latitude;
+
+    /**
+     * @Geocoder\Longitude
+     */
+    private $longitude;
+}
+
+$user = new User();
+$user->setAddress('Brandenburger Tor, Pariser Platz, Berlin');
+
+$em->persist($event);
+$em->flush();
+
+echo $user->getLatitude(); // will output 52.516325
+echo $user->getLongitude(); // will output 13.377264
+```