Mention here why ethernet time-out is 31.8 seconds on W5500

[0xCAFEDECAF]

SolarMeter/Solarmeter.ino

Line 47 in 8f2cf97

W5100.setRetransmissionCount(8);

Maybe good to put a comment here:

    // On W5500-based hardware, the timeout doubles per retry up to a maximum of 64000 units.
    // So by specifying 8 it will take:
    // 2000 + 4000 + 8000 + 16000 + 32000 + 64000 + 64000 + 64000 + 64000 = 318000 = 31,8 seconds(!)
    // See also: https://forum.arduino.cc/index.php?topic=430605.0