Document the new filter

readme.txt

@@ -25,6 +25,7 @@ For more history, see [this post](https://georgestephanis.wordpress.com/2013/08/
 Here is a list of action and filter hooks provided by the plugin:
 
 - `two_factor_providers` filter overrides the available two-factor providers such as email and time-based one-time passwords. Array values are PHP classnames of the two-factor providers.
+- `two_factor_providers_for_user` filter overrides the available two-factor providers for a specific user. Array values are instances of provider classes and the user object `WP_User` is available as the second argument.
 - `two_factor_enabled_providers_for_user` filter overrides the list of two-factor providers enabled for a user. First argument is an array of enabled provider classnames as values, the second argument is the user ID.
 - `two_factor_user_authenticated` action which receives the logged in `WP_User` object as the first argument for determining the logged in user right after the authentication workflow.
 - `two_factor_email_token_ttl` filter overrides the time interval in seconds that an email token is considered after generation. Accepts the time in seconds as the first argument and the ID of the `WP_User` object being authenticated.