Add comments explaining

conf/nginx-custom.conf

@@ -7,14 +7,16 @@
 	# DON'T DELETE THE LINE BELOW
 	# ADDITIONAL DIRECTIVES HERE
 
+	# Ensure we have the MTA-STS policy enabled
 	location = /.well-known/mta-sts.txt {
 		alias /var/lib/mailinabox/mta-sts.txt;
 	}
+
+	# Disable error logs for these
 	location = /robots.txt {
 		log_not_found off;
 		access_log off;
 	}
-
 	location = /favicon.ico {
 		log_not_found off;
 		access_log off;