Fix UI issues when using web search plugin with suggestions

Wox.Plugin/Features/IInstantQuery.cs

@@ -1,5 +1,9 @@
 namespace Wox.Plugin.Features
 {
+    /// <summary>
+    /// Represent plugin query will be executed in UI thread directly. Don't do long-running operation in Query method if you implement this interface
+    /// <remarks>This will improve the performance of instant search like websearch or cmd plugin</remarks>
+    /// </summary>
     public interface IInstantQuery
     {
         bool IsInstantQuery(string query);