Add esp-now support

[bjoernQ]

This adds support for esp-now ( https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/network/esp_now.html ) for all targets

closes #59

This also makes the xtask work on Windows (and hopefully doesn't break it on other OSes)

[MabezDev]

This is really cool!!! Async too 🤩! Working very well for me here, tried a few chips and all seem to work well :).

Just one small nit about features, my personal preference would be to unify to - but I'm not that bothered.

[bjoernQ]

Oh yes - I also prefer to use -
Done 😃

[MabezDev]

LGTM!