Add file upload

views/file/upload-result.hbs

@@ -0,0 +1,8 @@
+<div>
+  <h1>Upload Result</h1>
+  <p>File uploaded successfully.</p>
+  <p>File name: {{originalFilename}}</p>
+  <p>Right-click copy: <a href='/file/{{key}}'>{{key}}</a></p>
+  <p>Expires at {{expireTime}}</p>
+  <p><a href='/file'>Upload another file</a></p>
+</div>

views/file/upload.hbs

@@ -0,0 +1,9 @@
+<form method='post' enctype='multipart/form-data'>
+  <div>
+    <label for='file'>Choose file to upload</label>
+    <input type='file' id='file' name='file' multiple />
+  </div>
+  <div>
+    <button>Submit</button>
+  </div>
+</form>