TASK: Add info on how to integrate to README

Author: Nicolas Heist

README.md

@@ -5,7 +5,7 @@ that let you implement Two-Factor-Authentication easily.
 
 It depends on the Google2FA package https://github.com/antonioribeiro/google2fa
 
-## Installation & configuration
+## Installation
 
 Just add "yeebase/twofactorauthentication" as dependency to your composer.json and run a "composer update" in your project's root folder
 or simply execute:
@@ -14,4 +14,28 @@ composer require yeebase/twofactorauthentication
 ```
 from your project's root.
 
-TODO: Description of integration (abstract two-factor-auth controller, templates) and settings
+## Configuration
+The following part describes the integration of the Two-Factor-Authentication package into an existing Flow Application.
+The package can be integrated into a working application without applying any data migrations to the existing user base.
+Existing users will simply be treated as if Two-Factor-Authentication is disabled for them.
+
+### Provider
+Instead of using the default UsernamePasswordProvider, adapt your settings to use the following provider instead: `Yeebase\TwoFactorAuthentication\Security\Authentication\Provider\TwoFactorAuthenticationProvider`
+
+### Controllers and Templates
+This package brings two abstract controllers that contain all the methods necessary for login with and management of Two-Factor-Authentication.
+
+Instead of inheriting from the basic `AbstractAuthenticationController`, you should now inherit from `AbstractTwoFactorAuthenticationController` in your LoginController.
+The template of your login action should be adapted as described in the `TwoFactorUsernamePasswordToken` class.
+Additionally, you need to add a template for the `insertSecretAction` where the user can insert a secret.
+
+For the management of Two-Factor-Authentication you can inherit from the `AbstractAuthenticationManagementController`.
+Using this controller, it is necessary to provide exactly one template for the `configureAction`.
+When 2FA is disabled, it passes an `activationQrCode`-parameter to the template that holds the QR-Code which can be scanned by a GoogleAuthenticator.
+When 2FA is enabled, it does not pass any parameters to the template. From this point on, either the `enableAction` or the `disableAction` should be called
+with a `secret`-parameter given by the user to enable/disable 2FA.
+
+### Settings
+For the application to run, you should at least provide an `applicationName` which will be displayed in the Authenticator-App of the user.
+Furthermore, the `authenticationEntryPoint` should be specified. It configures where the user is redirected to, when he or she has to insert the secret for 2FA.
+This should usually be the LoginController of your package (if you inherited from `AbstractTwoFactorAuthenticationController` as described above).