Fix documentation (#1893)

Fix a tiny typo

Author: matteo-girardi

Sources/ComposableArchitecture/Effect.swift

@@ -129,7 +129,7 @@ extension EffectPublisher where Failure == Never {
   ///   struct State { … }
   ///   enum FeatureAction {
   ///     case factButtonTapped
-  ///     case faceResponse(TaskResult<String>)
+  ///     case factResponse(TaskResult<String>)
   ///   }
   ///   @Dependency(\.numberFact) var numberFact
   ///