Prevent IE Compatibility Mode

As discussed at https://meta.discourse.org/t/ie10-user-is-getting-your-browser-is-too-old/15289

config/nginx.sample.conf

@@ -42,6 +42,13 @@ server {
   # path to discourse's public directory
   set $public /var/www/discourse/public;
 
+  # Prevent Internet Explorer 10 "compatibility mode", which breaks Discourse.
+  # If other subdomains under your domain are supposed to use Internet Explorer Compatibility mode, 
+  # it may be used for this one too, unless you explicitly tell IE not to use it.  Alternatively,
+  # some people have reported having compatibility mode "stuck" on for some reason.
+  # (This will also prevent compatibility mode in IE 8 and 9, but those browsers aren't supported anyway.
+  add_header X-UA-Compatible "IE=edge";
+
   location / {
     root $public;