add comments for ConfigurableService

Easydict/NewApp/Utility/Protocol/ConfigurableService.swift

@@ -9,9 +9,11 @@
 import Foundation
 import SwiftUI
 
+/// A service can provide configuration view in setting
 protocol ConfigurableService {
     associatedtype T: View
-
+
+    /// Items in Configuration Form. Use ServiceStringConfigurationSection or other customize view.
     @ViewBuilder
     func configurationListItems() -> T
 }