Fix typo, add screenshots

templates/new.html

@@ -5,7 +5,7 @@
         <meta name="viewport" content="width=device-width, initial-scale=1.0">
     </head>
     <body>
-        <h1>Comfirm new Tx</h1>
+        <h1>Confirm new Tx</h1>
         <form action="/submit" method="POST">
             <textarea name="tx" rows="15" cols="40">{{ .Tx }}</textarea><br>
             <input type="submit">