Updated index ts to contain default export

types/index.d.ts

@@ -1,4 +1,5 @@
 import Vue from 'vue'
+import { PluginFunction } from "vue";
 
 export function install (vue: typeof Vue): void
 
@@ -10,3 +11,12 @@ export class FormWizard extends Wizard {}
 export class TabContent extends Tab {}
 export class WizardStep extends Step {}
 
+declare class VueFormWizard {
+  static install: PluginFunction<never>;
+
+  FormWizard: FormWizard;
+  TabContent: TabContent;
+  WizardStep: WizardStep;
+}
+
+export default VueFormWizard;