Updates following self review.

RiotSwiftUI/Modules/Onboarding/Avatar/OnboardingAvatarViewModelProtocol.swift

@@ -22,7 +22,10 @@ protocol OnboardingAvatarViewModelProtocol {
     @available(iOS 14, *)
     var context: OnboardingAvatarViewModelType.Context { get }
     
+    /// Update the view model to show the image that the user has picked.
     func updateAvatarImage(with image: UIImage?)
     
-    func update(with error: Error)
+    /// Update the view model to show that an error has occurred.
+    /// - Parameter error: The error to be displayed or `nil` to display a generic alert.
+    func processError(_ error: NSError?)
 }