feat: expose Resizable and ResizeHandle directives

* exposed directive in index.ts

* Update index.ts

src/index.ts

@@ -1,2 +1,4 @@
 export * from './resizable.module';
-export {ResizeEvent} from './interfaces/resizeEvent.interface'; // tslint:disable-line
+export {ResizeEvent} from './interfaces/resizeEvent.interface'; // tslint:disable-line
+export {Resizable} from './resizable.directive'; // tslint:disable-line
+export {ResizeHandle} from './resizeHandle.directive'; // tslint:disable-line