Add Switchbot Curtain support

[dshanske]

OpenWonderLabs/python-host@926a099

Looks like the coding is in the manufacturers repo.

[Danielhiversen]

I do not have the Switchbot Curtain, so I am not going to add support for it.

[dshanske]

@Danielhiversen Understandable. How would you feel about a PR? I'm not much of a Python programmer, but I think I could handle this. I want to try to upstream it into Home Assistant, where I believe you are also the maintainer of the component.

[Danielhiversen]

A pr would be great 👍

[daenny]

#13 initial work is done here.

[moretea]

#13 is merged, so AFAIK this ticket can be closed.