Fix a compile error for the macOS's example

Author: mshibanami

Example/Example (Shared)/ContentView.swift

@@ -67,13 +67,15 @@ struct ContentView: View {
                 .background(textBackgroundColor)
             }
 
+#if os(iOS)
             Section("No autocapitalization") {
                 ResizingTextView(
                     text: $text4,
                     placeholder: "Placeholder")
                 .autocapitalizationType(.none)
                 .background(textBackgroundColor)
             }
+#endif
         }
     }
 }