More nits

bonus/hkd.md

@@ -79,7 +79,7 @@ config :: Applicative f => Port -> FilePath -> Config f
 config = error "config"
 
 -- The forall in the constraint uses -XQuantifiedConstraints, available since
--- GHC 8.6.1 You could explicitly list them out instead:
+-- GHC 8.6.1 . You could explicitly list them out instead:
 -- instance (Show (f Port), Show (f FilePath)) => ...
 deriving instance (forall a . Eq (f a)) => Eq (Config f)
 deriving instance (forall a . Show (f a)) => Show (Config f)
@@ -172,7 +172,7 @@ extractConfig (Config (Last mp) (Last mdb)) = Config <$> mp <*> mdb
 Let's look at the expanded type of `extractConfig`:
 
 ```haskell ignore
-extractConfig :: PartialConf' -> Maybe (Conf')
+extractConfig :: PartialConf' -> Maybe Conf'
 extractConfig :: Config Last -> Maybe (Config Identity) -- expand type synonyms
 extractConfig :: Config Maybe -> Maybe (Config Identity) -- 'Last' is representationally 'Maybe'
 ```