Move code rendering to the backend & frontend improvements (#176)

Added Chroma & Goldmark

Added Mermaidjs

More languages supported

Add default values for gist links input

Added copy code from markdown blocks

templates/base/base_footer.html

@@ -30,9 +30,6 @@
         </div>
     </div>
 </div>
-
-<script type="module" src="{{ asset "hljs.ts" }}"></script>
-
 </div>
 </body>
 </html>