Add code comments

Author: nzagorchev

LeanplumSDK/LeanplumSDK/ClassesSwift/Actions/ActionManager+Configuration.swift

@@ -17,6 +17,9 @@ extension ActionManager {
         /// push notification will go into the queue and will be presented after in-app dismissal, otherwise
         /// the in-app is dismissed and the push notification's action is presented.
         ///
+        /// If `useAsyncHandlers` is `true`, this configuration will not have any effect and
+        /// push notification open will not dismiss the currently shown message.
+        ///
         /// - Default value: `true`
         public let dismissOnPushArrival: Bool
 

LeanplumSDK/LeanplumSDK/ClassesSwift/Actions/ActionManager.swift

@@ -15,6 +15,11 @@ import Foundation
     /// Set a new configuration to override a configuration option
     public var configuration: Configuration = .default
 
+    /// Setting `useAsyncHandlers` to `true` will have `prioritizeMessages` and
+    ///  `shouldDisplayMessage` handlers to be invoked in a background dispatch queue.
+    ///  OnMessage handlers will also be invoked in that background queue.
+    ///  Enabling `useAsyncHandlers` disables `ActionManager.Configuration.dismissOnPushArrival` and
+    ///  push notification open action will not dismiss currently shown message.
     public var useAsyncHandlers = false
     public let actionQueue = DispatchQueue(label: "leanplum.background_action_queue", qos: .background, target: DispatchQueue.global())