update readme for carthage

Author: nuclearace

README.md

@@ -85,13 +85,15 @@ let package = Package(
 Then import `import SocketIO`.
 
 ### Carthage
-Add these line to your `Cartfile`:
+Add this line to your `Cartfile`:
 ```
 github "socketio/socket.io-client-swift" ~> 12.1.0 # Or latest version
 ```
 
 Run `carthage update --platform ios,macosx`.
 
+Add the `Starscream` and `SocketIO` frameworks to your projects and follow the usual Carthage process.
+
 ### CocoaPods 1.0.0 or later
 Create `Podfile` and add `pod 'Socket.IO-Client-Swift'`: