fix(type): add "isSortable" to SmartFieldOptions interface (#1012)

Author: JustinMartinDev

types/index.d.ts

@@ -274,6 +274,7 @@ export interface SmartFieldOptions {
   description?: string;
   type: FieldType;
   isFilterable?: boolean;
+  isSortable?: boolean;
   isReadOnly?: boolean;
   isRequired?: boolean;
   reference?: string;