Add managed codec DSP and initial control server

docs/building.md

@@ -2,9 +2,11 @@
 
 ## .NET rewrite
 
-The initial managed wire/crypto slice is under `dotnet/`, targeting .NET 10. From the root:
+The managed wire/crypto, TLS, and codec/DSP slices are under `dotnet/`, targeting .NET 10.
+From the root (CMake and a C compiler are required for codec/DSP):
 
 ```powershell
+./dotnet/build-native.ps1
 dotnet restore dotnet/VoiceCat.slnx --locked-mode
 dotnet build dotnet/VoiceCat.slnx -c Release --no-restore
 dotnet test dotnet/VoiceCat.slnx -c Release --no-build