Adding new demo sound file and adding macro

conf/VACore.ini.proto

@@ -55,6 +55,8 @@ voices_dir = data/Voices
 # Macros can be defined and will be replaced with given value by the core. Usage: "$(MyMacroName)/file.abc" -> "MyValue/file.abc"
 # Macros are substituted forwardly by key name order (use with care), otherwise stay untouched: A = B; C = $(A) -> $(C) is B
 
+DemoSound = WelcomeToVA.wav
+
 DefaultHRIR = HRIR/ITA-Kunstkopf_HRIR_AP11_Pressure_Equalized_3x3_256.v17.ir.daff
 HumanDir = Directivity/Singer.v17.ms.daff
 Trumpet = Directivity/Trumpet1.v17.ms.daff