Improve WaitForSelector docs (#1319)

Author: kblok

lib/PuppeteerSharp/WaitForSelectorOptions.cs

@@ -8,17 +8,19 @@
     public class WaitForSelectorOptions
     {
         /// <summary>
-        /// Maximum time to wait for in milliseconds. Pass 0 to disable timeout.
+        /// Maximum time to wait for in milliseconds. Defaults to `30000` (30 seconds). 
+        /// Pass `0` to disable timeout. 
+        /// The default value can be changed by using <seealso cref="Page.DefaultTimeout"/>  method
         /// </summary>
         public int? Timeout { get; set; }
 
         /// <summary>
-        /// Wait for selector to become visible.
+        /// Wwit for element to be present in DOM and to be visible.
         /// </summary>
         public bool Visible { get; set; }
 
         /// <summary>
-        /// Wait for selector to become hidden.
+        /// Wait for element to not be found in the DOM or to be hidden.
         /// </summary>
         public bool Hidden { get; set; }
     }