config: Better explain linelen

irc/config.go

@@ -342,7 +342,7 @@ func LoadConfig(filename string) (config *Config, err error) {
 		}
 	}
 	if config.Limits.LineLen.Tags < 512 || config.Limits.LineLen.Rest < 512 {
-		return nil, errors.New("Line length must be 512 or greater")
+		return nil, errors.New("Line lengths must be 512 or greater (check the linelen section under server->limits)")
 	}
 
 	return config, nil

oragono.yaml

@@ -204,6 +204,7 @@ limits:
     chan-list-modes: 60
 
     # maximum length of IRC lines
+    # this should generally be 1024-2048, and will only apply when negotiated by clients
     linelen:
         # tags section
         tags: 2048