docs: Add SoapySDR note to release (closes merbanan#2757)

Author: zuckschwerdt

.deploy/WINDOWS-MINGWW64.txt

@@ -9,7 +9,10 @@ For the SoapySDR builds you need PothosSDR installed https://downloads.myriadrf.
 Any recent version should work, currently built with 2021.07.25-vc16:
 https://downloads.myriadrf.org/builds/PothosSDR/PothosSDR-2021.07.25-vc16-x64.exe
 When installing choose "Add PothosSDR to the system PATH for the current user"
+
 Remove the SoapySDR.dll in this directory, it's for testing only and won't load any driver modules.
+To run with SoapySDR you need to copy `rtl_433.exe` to `PothosSDR\bin` (usually `C:\Program Files\PothosSDR`).
+Otherwise SoapySDR driver modules won't be found.
 
 An alternative to installing SoapySDR from PothosSDR is to extract the installer
 and copy the builds (.exe) from this release to the `bin` directory in PothosSDR.

.deploy/WINDOWS-MSVC.txt

@@ -5,6 +5,10 @@ Any recent version should work, currently built with 2021.07.25-vc16:
 https://downloads.myriadrf.org/builds/PothosSDR/PothosSDR-2021.07.25-vc16-x64.exe
 When installing choose "Add PothosSDR to the system PATH for the current user"
 
+Remove the SoapySDR.dll in this directory, it's for testing only and won't load any driver modules.
+To run with SoapySDR you need to copy `rtl_433-rtlsdr-soapysdr.exe` to `PothosSDR\bin` (usually `C:\Program Files\PothosSDR`).
+Otherwise SoapySDR driver modules won't be found.
+
 For the TLS builds (mqtts and influxs) you need OpenSSL installed.
 E.g. install Chocolatey https://chocolatey.org/install
 then run `choco install openssl.light`