make backend serve static content

remove style template and use static style.css file

src/views/index.ejs

@@ -5,8 +5,8 @@
     <meta http-equiv="X-UA-Compatible" content="IE=edge">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>UPN-QR | Open generator for UPN QR codes</title>
+    <link rel="stylesheet" href="/public/style.css">
 </head>
-<%- include('../template/style.ejs') -%>
 <style>
 section div {
     padding-left: 25px;