refactor(qrgen): generaliza "URL" into "data", correctly use FlaskWTForms

app/templates/main.html

@@ -10,8 +10,9 @@
 <br/>
 <p>
 <form action="" method="post">
+	{{ form.csrf_token }}
 	<div class="input text">
-		{{ form.url.label}}	{{ form.url }} </div>
+		{{ form.user_data.label }}	{{ form.user_data }} </div>
 
 	<div class="input submit">
 		<input type="submit" value="Generate"</div>
@@ -21,8 +22,8 @@
 <hr>
 
 <p>
-<div><img src="{{ genurl }}?size=512&data={{ target_url }}"> <br/>
-	{{ target_url }}
+<div><img src="{{ genurl }}?size=512&data={{ data | urlencode }}"> <br/>
+	{{ data }}
 </div>
 </p>
 </center>