Additional documentation

[pcmihnea]

Hi,
Since there's not a lot of repositories covering this obscure and (as-of-late) half-working weather station, I've also took upon the challenge on integrating it in HomeAssistant. For that, I've documented the inner-workings on https://github.com/pcmihnea/HA_WMR500 - it may provide useful information that you could include in your repo.