pipewire: mention xdg autostart files

Author: paper42

src/config/media/pipewire.md

@@ -14,6 +14,15 @@ environment or [startx](../graphical-session/xorg.md#startx). The `pipewire`
 package provides `pipewire` and `pipewire-pulse` system services, but they are
 not recommended for a typical setup.
 
+The `pipewire` package ships XDG Autostart files for `pipewire` and
+`pipewire-pulse` in `/usr/share/doc/pipewire`. If your desktop environment
+supports the XDG Autostart specification, you can enable pipewire by symlinking
+the files from documentation to the XDG autostart directory:
+
+```
+# ln -s /usr/share/pipewire/pipewire.desktop /etc/xdg/autostart/pipewire.desktop
+```
+
 ## PulseAudio replacement
 
 Before starting `pipewire-pulse`, make sure that the PulseAudio service is