updated meta tags

docs/theme/main.html

@@ -22,10 +22,11 @@
   <meta property="og:image:height" content="540" />
   <!-- Twitter stuff -->
   <meta name="twitter:card" content="summary_large_image" />
-  <meta name="twitter:site" content="Roadmap" />
-  <meta name="twitter:creator" content="schdesign" />
+  <meta name="twitter:site" content="@schdesign" />
+  <meta name="twitter:creator" content="@schdesign" />
   <meta name="twitter:title" content="{{ title }}" />
   <meta name="twitter:description" content="{{ description }}" />
   <meta name="twitter:image" content="https://logotar.schdesign.hu/assets/database/Simonyi/schdesign/schdesign.png" />
+  <meta name="twitter:image:alt" content="Schönherz Design Studio" />
   <!-- Other stuff -->
 {% endblock %}
\ No newline at end of file