Update readme

README.md

@@ -55,6 +55,86 @@ Here is an example
         console.log(err);
     });
 
+
+#### Sub Resources
+
+There are some values that return a link.  To make it easier to deal with these, there are corresponding getters for those properties.
+
+For example,  a call to `getPerson(1)` might return this json:
+
+    {
+        "name": "Luke Skywalker",
+        "height": "172",
+        "mass": "77",
+        "hair_color": "blond",
+        "skin_color": "fair",
+        "eye_color": "blue",
+        "birth_year": "19BBY",
+        "gender": "male",
+        "homeworld": "http://swapi.co/api/planets/1/",
+        "films": [
+            "http://swapi.co/api/films/1/",
+            "http://swapi.co/api/films/2/",
+            "http://swapi.co/api/films/3/",
+            "http://swapi.co/api/films/6/"
+        ],
+        "species": [],
+        "vehicles": [
+            "http://swapi.co/api/vehicles/14/",
+            "http://swapi.co/api/vehicles/30/"
+        ],
+        "starships": [
+            "http://swapi.co/api/starships/12/",
+            "http://swapi.co/api/starships/22/"
+        ],
+        "created": "2014-12-09T13:50:51.644000Z",
+        "edited": "2014-12-20T21:17:56.891000Z",
+        "url": "http://swapi.co/api/people/1/"
+    }
+
+taking "homeworld" as an example,  you can now call `getHomeworld()`, which will return a Promise
+
+    getHomeworld().then(function (result) {
+        console.log(result);
+    });
+
+This might produce some json like this:
+
+
+    {
+        "name": "Tatooine",
+        "rotation_period": "23",
+        "orbital_period": "304",
+        "diameter": "10465",
+        "climate": "arid",
+        "gravity": "1 standard",
+        "terrain": "desert",
+        "surface_water": "1",
+        "population": "200000",
+        "residents": [
+            "http://swapi.co/api/people/1/",
+            "http://swapi.co/api/people/2/",
+            "http://swapi.co/api/people/4/",
+            "http://swapi.co/api/people/6/",
+            "http://swapi.co/api/people/7/",
+            "http://swapi.co/api/people/8/",
+            "http://swapi.co/api/people/9/",
+            "http://swapi.co/api/people/11/",
+            "http://swapi.co/api/people/43/",
+            "http://swapi.co/api/people/62/"
+        ],
+        "films": [
+            "http://swapi.co/api/films/1/",
+            "http://swapi.co/api/films/3/",
+            "http://swapi.co/api/films/4/",
+            "http://swapi.co/api/films/5/",
+            "http://swapi.co/api/films/6/"
+        ],
+        "created": "2014-12-09T13:50:49.641000Z",
+        "edited": "2014-12-21T20:48:04.175778Z",
+        "url": "http://swapi.co/api/planets/1/"
+    }
+
 ### Note
 
 This API tries to follow the API for the Python helper lib here: https://github.com/phalt/swapi-python