add shouldbreakafterconifg workaround to readme

README.md

@@ -142,6 +142,14 @@ void configModeCallback (WiFiManager *myWiFiManager) {
 ##### Save settings
 This gets called when custom parameters have been set **AND** a connection has been established. Use it to set a flag, so when all the configuration finishes, you can save the extra parameters somewhere.
 
+
+IF YOU NEED TO SAVE PARAMETERS EVEN ON WIFI FAIL OR EMPTY, you must set `setBreakAfterConfig` to true, or else saveConfigCallback will not be called.
+
+```C++
+//if this is set, it will exit after config, even if connection is unsuccessful.
+    void          setBreakAfterConfig(boolean shouldBreak);
+```
+
 See [AutoConnectWithFSParameters Example](https://github.com/tzapu/WiFiManager/tree/master/examples/AutoConnectWithFSParameters).
 ```cpp
 wifiManager.setSaveConfigCallback(saveConfigCallback);