chore: update README for authenticated consent

Author: andresilveirah

README.md

@@ -158,6 +158,13 @@ export default function App() {
 )
 ```
 
+## Implementing authenticated consent
+In a nutshell, you provide an identifier for the current user (username, user id, uuid or any unique string) and we'll take care of associating the consent profile to that identifier.
+
+In order to use the authenticated consent all you need to do is replace `.loadMessage()` with `.loadMessage({ authId: "JohnDoe"}))`.
+
+If our APIs have a consent profile associated with that token `"JohnDoe"` the SDK will bring the consent profile from the server, overwriting whatever was stored in the device. If none is found, the session will be treated as a new user.
+
 ## Complete App examples
 
 Complete app examples for iOS and Android can be found in the [`/example`](/example/) folder of the SDK.