Added YouTube button

Author: RazviOverflow

_layouts/default.html

@@ -40,6 +40,7 @@ <h2 style="color: #666;">{{ site.description | default: site.github.project_tagl
             <a href="{{ site.github.tar_url }}" class="btn">Download as .tar.gz</a>
           {% endif %}
           <a href="/" class="btn btn-root-page"><span class="icon"></span>Root page</a>
+          <a href="https://www.youtube.com/@RazviOverflow" class="btn btn-youtube"><span class="icon"></span>YouTube</a>
           <a href="https://twitter.com/razvieu?lang=en" class="btn btn-twitter"><span class="icon"></span>Twitter</a>
           <a href="{{ site.github.repository_url }}" class="btn btn-github"><span class="icon"></span>View on GitHub</a>
         </section>