Update documentation.

Author: jaclync

docs/NETWORKING.md

@@ -45,6 +45,7 @@ At the moment, we provide four implementations of `URLRequestConvertible`:
 * [`JetpackRequest`](../Networking/Networking/Requests/JetpackRequest.swift) represents a Jetpack-Tunneled WordPress.com 
 * [`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
 
 ## [`Mapper`](../Networking/Networking/Mapper/Mapper.swift)
 A protocol that abstracts the different parsers.

docs/architecture-overview.md

@@ -171,10 +171,12 @@ of performing this task for us:
 
 3.  **AuthenticatedRequest**
 
-        Injects a set of Credentials into anything that conforms to the URLConvertible protocol. Usually wraps up
+        Injects a set of Credentials and a custom user-agent header into anything that conforms to the URLConvertible protocol. Usually wraps up
         a DotcomRequest (OR) JetpackRequest.
 
+4. **UnauthenticatedRequest**
 
+        Wraps up a `URLConvertible` with a custom user-agent header. Used when the request does not require WordPress.com authentication.
 
 ### Remote Endpoints