Update README.md

Author: auser

README.md

@@ -84,7 +84,11 @@ Once you have linked this library, run the following command in the root directo
 (cd ios && pod install)
 ```
 
-Finally, open the created `.xcworkspace` in the `ios/` directory (**NOT THE `.xproj` file**) when it's complete.
+Open the created `.xcworkspace` in the `ios/` directory (**NOT THE `.xproj` file**) when it's complete.
+
+When working on iOS 10, we'll need to enable _Keychain Sharing Entitlement_ in _Capabilities_ of the build target of `io.fullstack.oauth.AUTH_MANAGER`.
+
+![](./resources/capabilities.png)
 
 ### Android setup