Change docx folder to more appropriate "file" folder

src/file/paragraph/properties.ts

@@ -0,0 +1,13 @@
+// http://officeopenxml.com/WPparagraphProperties.php
+import { XmlComponent } from "../xml-components";
+
+export class ParagraphProperties extends XmlComponent {
+
+    constructor() {
+        super("w:pPr");
+    }
+
+    public push(item: XmlComponent): void {
+        this.root.push(item);
+    }
+}