Update subscribe/unsubscribe details in README.md (#12)

Author: kettlebell

README.md

@@ -81,17 +81,17 @@ fireOnChange = do
 Subscriptions registered using these functions are automatically tracked by Halo.
 
 ```purescript
-subscribe :: forall props state action m. FRP.Event action -> HaloM props state action m SubscriptionId
+subscribe :: forall props ctx state action m. Emitter action -> HaloM props ctx state action m SubscriptionId
 
-unsubscribe :: forall m action state props. SubscriptionId -> HaloM props state action m Unit
+unsubscribe :: forall props ctx state action m. SubscriptionId -> HaloM props ctx state action m Unit
 ```
 
-`FRP.Event` is from the `purescript-event` library.
+`Emitter` is from the `purescript-halogen-subscriptions` library.
 
 There is also a version for subscriptions that want to unsubscribe themselves:
 
 ```purescript
-subscribe' :: forall m action state props. (SubscriptionId -> FRP.Event action) -> HaloM props state action m SubscriptionId
+subscribe' :: forall props ctx state action m. (SubscriptionId -> Emitter action) -> HaloM props ctx state action m SubscriptionId
 ```
 
 Any subscriptions that remain when the component is unmounted are automatically unsubscribed. This prevents requiring manual clean up in the `Finalize` lifecycle event. Also note that new subscriptions will not be created once the `Finalize` event has been fired.