Added missing UsePersian method to interface.

TelegramBotBase/Builder/Interfaces/ILanguageSelectionStage.cs

@@ -22,6 +22,12 @@ public interface ILanguageSelectionStage
     /// <returns></returns>
     IBuildingStage UseGerman();
 
+    /// <summary>
+    ///     Selects persian as the default language for control labels.
+    /// </summary>
+    /// <returns></returns>
+    IBuildingStage UsePersian();
+
     /// <summary>
     ///     Selects a custom language as the default language for control labels.
     /// </summary>