Add ipfs.files.add example.

Author: hackergrrl

README.md

@@ -92,6 +92,33 @@ an array of [DAGNode][]s.
 
 If no `callback` is passed, a promise is returned.
 
+```js
+// array in => array out
+var files = [
+  {
+    path: '/tmp/myfile.txt',
+    stream: fs.createReadStream('/tmp/myfile.txt')
+  }
+]
+ipfs.files.add(files, function (err, dagNodes) {
+  // 'res' will be an array of DAGNodes
+})
+```
+
+```js
+// no input => duplex stream out
+ipfs.files.add(function (err, stream) {
+  stream.on('data', function (dagNode) {
+    // ...
+  })
+
+  stream.write({path: <path to file>, stream: <readable stream>})
+  // write as many as you want
+
+  stream.end()
+})
+```
+