wrap within directory when adding files to preserve original filename

src/index.js

@@ -25,13 +25,17 @@ async function initialize() {
     console.log('ipfs node id: ' + node_info.id);
     const pinList = document.createElement('ul');
     const fileReader = new FileReader();
-    fileReader.onload = async function() {
-        const pin = await node.add(fileReader.result);
+    fileReader.onload = async function(event) {
+        const file = {
+            path: fileSelector.files[0].name,
+            content: fileReader.result,
+        };
+        const pin = await node.add(file, {wrapWithDirectory: true});
         pinList.appendChild(create_pin_tag(node, pin.cid));
     };
     const fileSelector = document.createElement('input');
     fileSelector.type = 'file';
-    fileSelector.onchange = function(x) {
+    fileSelector.onchange = function() {
         fileReader.readAsBinaryString(fileSelector.files[0]);
     };
     document.body.appendChild(fileSelector);