Add image demo

demo/demo5.js

@@ -0,0 +1,11 @@
+const docx = require('../build');
+
+var doc = new docx.File();
+
+const image = doc.createImage("./demo/penguins.jpg");
+
+
+var exporter = new docx.LocalPacker(doc);
+exporter.pack('My Document');
+
+console.log('Document created successfully at project root!');