Improve import alias

@file/ and @export/ instead of file/ and export/ etc

src/file/document/document.ts

@@ -1,5 +1,5 @@
 // http://officeopenxml.com/WPdocument.php
-import { XmlComponent } from "file/xml-components";
+import { XmlComponent } from "@file/xml-components";
 import { ConcreteHyperlink, Paragraph } from "../paragraph";
 import { Table } from "../table";
 import { TableOfContents } from "../table-of-contents";