Add support for the new MAX3221E boards

[jLynx]

Would it be possible to add support for the MAX3221E based boards.

Everything seems to be identical apart from the main IC

[xxxajk]

MAX3221E is an RS232 IC... looks like you got yourself a fake board, with a fake IC. Congratulations.

[Lauszus]

MAX3221E is a RS232 IC. Are you sure it really is a MAX3221E on your board?

[jLynx]

Yep, it is. It's also a bit of a paperweight. So I was able to get a full refund on Aliexpress. I have since ordered another one from another seller. Hopefully this one doesn't swap out the photos after ordering.