Add RESTRequest to the documentation.

Author: selanthiraiyan

docs/NETWORKING.md

@@ -43,6 +43,7 @@ A protocol the abstracts the actual URL requests.
 At the moment, we provide four implementations of `URLRequestConvertible`:
 * [`DotcomRequest`](../Networking/Networking/Requests/DotcomRequest.swift) models requests to WordPress.com
 * [`JetpackRequest`](../Networking/Networking/Requests/JetpackRequest.swift) represents a Jetpack-Tunneled WordPress.com 
+* [`RESTRequest`](../Networking/Networking/Requests/RESTRequest.swift) represents a REST API request sent to the site (instead of through the Jetpack tunnel) directly.  
 * [`AuthenticatedRequest`](../Networking/Networking/Requests/AuthenticatedRequest.swift) Wraps up a `URLRequestConvertible` instance, and injects credentials (username and token) when required
 * [`WordPressOrgRequest`](../Networking/Networking/Requests/WordPressOrgRequest.swift) model requests to the WordPress.org REST API.
 * [`UnauthenticatedRequest`](../Networking/Networking/Requests/UnauthenticatedRequest.swift) Wraps up a `URLRequestConvertible` instance, and injects a custom user-agent header