Update lib/local-cluster/lib/Cardano/Wallet/Launch/Cluster/Monitoring…

…/Http/ApiT.hs

Co-authored-by: Heinrich Apfelmus <heinrich.apfelmus@iohk.io>

lib/local-cluster/lib/Cardano/Wallet/Launch/Cluster/Monitoring/Http/ApiT.hs

@@ -12,6 +12,12 @@ import GHC.Generics
     ( Generic
     )
 
--- | A newtype wrapper to avoid orphan instances
+-- | A value of type 'ApiT'@ a@ is equivalent to a value of type @a@.
+-- However, the type 'ApiT'@ a@ has a custom JSON encoding that
+-- is independent of the original definition of @a@.
+--
+-- In other words, the 'ApiT' type constructor allows us to separate the
+-- concern of presenting @a@ in a HTTP/JSON interface from
+-- the definition of @a@ as a data type.
 newtype ApiT a = ApiT {unApiT :: a}
     deriving newtype (Eq, Show, Generic)