Add a shortcut to a request's response body since it's what it'll be used for most of the time.

examples/jsonplaceholer.yml

@@ -7,5 +7,5 @@ GET /posts/:
 POST /posts/:
   alias: new-post
 
-GET /users/$posts.response.body.0.userId:
+GET /users/$posts.body.0.userId:
   alias: post-user

request.js

@@ -79,6 +79,8 @@ class Request {
 						}
 					};
 
+					results.body = results.response.body;
+
 					cache.add(`$${this.ALIAS}`, results);
 
 					resolve(results);