Add information about how to compile this file. The code in this tutorial also requires `gstreamer-audio-1.0`, so we cannot use the commands from the previous tutorial. Closes https://gitlab.freedesktop.org/gstreamer/gst-docs/-/merge_requests/164/ Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1324>
Prerequisite for our removing it from the cerbero build, see https://gitlab.freedesktop.org/gstreamer/cerbero/-/merge_requests/760 Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1199>