Update banner image path in main.html to correct asset location

Author: Vadym-Kharchenko

material/overrides/main.html

@@ -10,7 +10,7 @@
 {% endblock %}
 {% block announce %}
 <style>.md-banner {
-  background-image: url(/assets/img/banner_neon_depth.svg);
+  background-image: url(/info/assets/img/banner_neon_depth.svg);
   background-size: cover;
   background-position: center;
 }</style>