Add info about SDRplay support

[AsciiWolf]

I am using welle.io with my SDRplay RSPdx on Fedora 35 and it works great, including additional features like antenna port selection. :-)

[AlbrechtL]

Great!

Feel free to add the support of SDRplay including a how to to our website https://www.welle.io. You can do this via a pull request to the websites repository https://github.com/AlbrechtL/welle.io/tree/gh-pages

[AsciiWolf]

Hello Albrecht, I will probably wait until #562 gets fixed because now, I have to manually check and uncheck the "Automatic RF gain", then set the "Manual gain" slider every time I start welle.io. This issue may be related to osmocom/#5562, however that issue was fixed downstream in my Linux distribution (Fedora), but is still present in welle.io.

[AlbrechtL]

Pull request are always welcome!