Add initial APKBUILD for shairport-sync and nqptp

shairport-sync/shairport-sync.initd

@@ -0,0 +1,11 @@
+#!/sbin/openrc-run
+
+description="A synchronous (multi-room-capable) AirPlay receiver."
+command="/usr/bin/shairport-sync"
+command_background="yes"
+
+pidfile="/run/$RC_SVCNAME.pid"
+
+depend() {
+	need net localmount avahi-daemon nqptp
+}