add support for floating drawings

- added need elements and test for them

src/file/drawing/floating/align.ts

@@ -0,0 +1,10 @@
+// http://officeopenxml.com/drwPicFloating-position.php
+import { XmlComponent } from "file/xml-components";
+import { HorizontalPositionAlign, VerticalPositionAlign } from "./floating-position";
+
+export class Align extends XmlComponent {
+    constructor(value: HorizontalPositionAlign | VerticalPositionAlign) {
+        super("wp:align");
+        this.root.push(value);
+    }
+}