Added docs.

Author: ivanvorobei

Sources/SparrowKit/UIKit/Classes/SPController.swift

@@ -27,6 +27,9 @@ import UIKit
  */
 open class SPController: UIViewController {
 
+    /**
+     SparrowKit: Indicator controller did present any time before or not.
+     */
     open var didPresent: Bool = false
 
     // MARK: - Init