Fix #10. Add note about board types.

README.md

@@ -98,6 +98,11 @@ in these instructions I describe use of their command line tool.
 1. Purchase a suitable radio (see above)
 2. Install [PlatformIO](https://platformio.org/platformio-ide)
 3. Download this git repo and cd into it
-4. Plug the radio into your USB port
-4. Type "pio run -t upload" (This command will fetch dependencies, build the project and install it on the board via USB)
-5. Platform IO also installs a very nice VisualStudio Code based IDE, see their [tutorial](https://docs.platformio.org/en/latest/tutorials/espressif32/arduino_debugging_unit_testing.html) if you'd like to use it
+4. Edit configuration.h and comment out *one* of the following two lines (depending on which board you are using):
+```
+// #define T_BEAM_V10  
+#define HELTEC_LORA32
+```
+5. Plug the radio into your USB port
+6. Type "pio run -t upload" (This command will fetch dependencies, build the project and install it on the board via USB)
+7. Platform IO also installs a very nice VisualStudio Code based IDE, see their [tutorial](https://docs.platformio.org/en/latest/tutorials/espressif32/arduino_debugging_unit_testing.html) if you'd like to use it