Found while working on GStreamer-rs documentation, some enums had this
bit of text pasted verbatim in the enum documentation rather than
attached to the enum-variant. Fortunately it seems these in WebRTC and
D3D11 are the only ones matching the non-@-prefixed pattern:
^ \* GST_\w+:\s*\w+
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2118>