Document WatchKit support

[grav]

Thanks for creating this project

I experimented with this on WatchKit, and I found that the only API that works is setting attributed text on a WKInterfaceLabel, and that there seems to be no support for links, images, quote or code. Can you confirm this?

For this subset though, it works very well :-)

[chrisdhaan]

Images is not included in the WatchKit build. Links, quotes, and code likely don't work because I haven't written any code to overwrite the WKInterfaceLabel to render the colors correctly. I'll look into if that is possible. Thanks for pointing this out @grav