Enable dark theme.

This should hopefully carry over into the browser and such so I don't get blinded.

ansible/roles/poudrierenginx/files/nginx.conf

@@ -9,6 +9,10 @@ http {
     include       mime.types;
     default_type  application/octet-stream;
 
+    types {
+        text/plain log;
+    }
+
     sendfile        on;
     tcp_nopush     on;
     tcp_nodelay    on;