Fixing docs with docs link and title renaming.

README.md

@@ -2,11 +2,11 @@
 
 It's very common to build software with multiple components: a mobile app, Web back-end and etc. You Drive app should be in the same category and requires you to manage user authorization for multiple entities of the sample app. Google's OAuth 2.0 implementation provides some extentions to address the following cases:
 
-* Help server-side to retrieve an acess token for itself, when user authorizes the Android app.
-* Help Android app to identify user if user is once authorized with the server-side.
+* Resolving user identity on Android apps without requiring the user to sign-in, if the user has already connected himself/herself on the Web application.
+* Enabling an Android app to retrieve an exchange code for its server-side component.
 
 
-**Warning**: These extentions are only available if authorization scopes contain `https://www.googleapis.com/auth/plus.login` to use Google+ sign-in.
+**Warning**: These extentions are only available if authorization scopes contain `https://www.googleapis.com/auth/plus.login` for now.
 
 ## Configuration
 
@@ -22,20 +22,30 @@ final private List<String> SCOPES = Arrays.asList(new String[]{
 });
 ~~~~
 
-## Retrieve exchange code for server-side
+## Resolve user identity with no sign-in
+
+Retrieve an JSON Web Token (JWT) to identify user. You can exchange the JWT payload with your server-side to decrypt and identify user with his/her email address.
+
+~~~java
+String scope = "audience:server:client_id:" + CLIENT_ID;
+String idToken = GoogleAuthUtil.getToken(context, accountName, scope);
+~~~
+
+## Retrieve access/refresh tokens for the server
 
 ~~~java
 String scope = String.format("oauth2:server:client_id:%s:api_scope:%s", CLIENT_ID, TextUtils.join(" ", SCOPES));
 String exchangeCode = GoogleAuthUtil.getToken(context, accountName, scope);
 ~~~
 
-## Retrieve a JWT to identify user on server-side
+Send the code to the server and exchange your code with Google to retrieve an access and a refresh token for your server-side.
 
-Retrieve an JSON Web Token (JWT) to identify user. You can exchange the JWT payload with your server-side to decrypt and identify user with his/her email address.
+    POST https://accounts.google.com/o/oauth2/token
+    Content-Type: application/x-www-form-urlencoded
 
-~~~java
-String scope = "audience:server:client_id:" + CLIENT_ID;
-String idToken = GoogleAuthUtil.getToken(context, accountName, scope);
-~~~
+    code=<exchangeCode>&
+    client_id=<CLIENT_ID>&
+    client_secret=<CLIENT_SECRET>&
+    grant_type=authorization_code
 
-More details are explained on [Google's OAuth 2.0 public docs](https://developers.google.com/accounts/docs/CrossClientAuth).
+More details are explained on [Google Drive's Cross-client Identity](https://developers.google.com/drive/auth/android#cross-client_identity) docs.