[Minor] Ratelimit - improve config file

conf/modules.d/ratelimit.conf

@@ -30,6 +30,10 @@ ratelimit {
     #}
     # If symbol is specified, then it is inserted instead of setting result
     #symbol = "R_RATELIMIT";
+
+    # If info_symbol is specified, then it is inserted next to set the result
+    #info_symbol = "R_RATELIMIT_INFO";
+
     whitelisted_rcpts = "postmaster,mailer-daemon";
     max_rcpt = 5;