Add async_ and asyncWithUnmask_

Co-authored-by: Jan Beinke <git@janbeinke.com>

src/Quasar/Async.hs

 module Quasar.Async (
   -- * Async/await
   MonadAsync(..),
+  async_,
+  asyncWithUnmask_,
 
   -- * Task
   Task,
@@ -80,6 +82,14 @@ liftUnmask unmask action = do
   liftIO $ unmask $ runReaderT action value
 
 
+async_ :: MonadAsync m => m () -> m ()
+async_ = void . async
+
+asyncWithUnmask_ :: MonadAsync m => ((forall a. m a -> m a) -> m ()) -> m ()
+asyncWithUnmask_ action = void $ asyncWithUnmask action
+
+
+
 
 -- | A task that is running asynchronously. It has a result and can fail.
 -- The result (or exception) can be aquired by using the `IsAwaitable` class (e.g. by calling `await` or `awaitIO`).