move apis into rom/modules/main for shell compatibility

sys/modules/opus/sound.lua

@@ -0,0 +1,17 @@
+local peripheral  = _G.peripheral
+
+local Sound = {
+	_volume = 1,
+}
+
+function Sound.play(sound, vol)
+	peripheral.find('speaker', function(_, s)
+		s.playSound('minecraft:' .. sound, vol or Sound._volume)
+	end)
+end
+
+function Sound.setVolume(volume)
+	Sound._volume = math.max(0, math.min(volume, 1))
+end
+
+return Sound