Update on_boot_config.md (#1186)

Added verbiage for clarity

docs/on_boot_config.md

@@ -33,10 +33,11 @@ After applying the settings, the file is automatically deleted.
     If there was a string `FIRST_BOOT=1` in the file, do not remove it.
     This is the trigger needed to initialize the OS at the first boot.
     On the contrary, if the file pikvm.txt does not exist, you should not add this line.
-
+   
 5. Unmount partition and return the memory card to PiKVM.
 
 6. A few things to keep in mind:
+    * Note that after applying the settings, the pikvm.txt file will be deleted.
     * WPA3 is not supported. Enable WPA2 on your router.
     * There is a possibility that, in countries that support channel 13, the device will not connect.
         You will need to configure your router to disable channels 12-14 or disable Auto scan mode.