update header

Author: GaspardKirira

vix-site/index.html

@@ -62,6 +62,7 @@
       content="https://vixcpp.com/assets/logo/vix-logo.png"
     />
     <meta name="twitter:site" content="@vix_cpp" />
+    <meta name="mobile-web-app-capable" content="yes">
 
     <!-- Favicons / App icons (single source: /assets/pwa) -->
     <link rel="icon" href="/assets/pwa/favicon.ico" />