chore(client): remove insight-app-sec-validation meta tag

relates-to #26

client/index.html

@@ -11,14 +11,14 @@
     <link rel="icon" type="image/png" sizes="32x32" href="/favicons/favicon-32x32.png" />
     <link rel="icon" type="image/png" sizes="16x16" href="/favicons/favicon-16x16.png" />
     <meta name="theme-color" content="#ffffff" />
-    <meta name="insight-app-sec-validation" content="38936a45-0c2c-4f3c-89c0-a26817f2a5a8" />
+
     <script id="config" type="application/json" src="/api/config"></script>
 
     <!--
       manifest.json provides metadata used when your web app is installed on a
       user's mobile device or desktop. See https://developers.google.com/web/fundamentals/web-app-manifest/
     -->
-    <link rel="manifest" href="manifest.json" />
+    <link rel="manifest" href="/manifest.json" />
     <title>Broken Crystals</title>
     <!-- Google Fonts -->
     <link