CH340 Drivers

[jda0]

• Add support for Mac following steps at StackExchange
• Include copies of CH340 drivers for Win/Mac in repo for safekeeping (correct url for Win is http://www.wch.cn/download/CH341SER_ZIP.html)?

[willprice]

The Wemos wiki actually has a link for the drivers: https://wiki.wemos.cc/products:d1:d1 we should probably link there.