update docs

Author: jdegoes

MODULE.md

@@ -111,14 +111,10 @@
 
 ### Values
 
-    _tail :: forall f a. Cofree f a -> Trampoline (f (Cofree f a))
-
     head :: forall f a. Cofree f a -> a
 
     mkCofree :: forall f a. a -> f (Cofree f a) -> Cofree f a
 
-    mkCofree' :: forall f a. a -> Lazy (f (Cofree f a)) -> Cofree f a
-
     tail :: forall f a. Cofree f a -> f (Cofree f a)