Add Quasar module that re-exports core modules

quasar.cabal

@@ -83,6 +83,7 @@ library
     transformers,
     unordered-containers,
   exposed-modules:
+    Quasar
     Quasar.Async
     Quasar.Awaitable
     Quasar.Disposable

src/Quasar.hs

+module Quasar (
+  module Quasar.Async,
+  module Quasar.Awaitable,
+  module Quasar.Disposable,
+  module Quasar.Observable,
+  module Quasar.ResourceManager,
+) where
+
+import Quasar.Async
+import Quasar.Awaitable
+import Quasar.Disposable
+import Quasar.Observable
+import Quasar.ResourceManager