markdown: mediatype-video-raw.md: Fix broken formatting
Please see https://gstreamer.freedesktop.org/documentation/additional/design/mediatype-video-raw.html?gi-language=c#formats from v210
format.
Please see https://gstreamer.freedesktop.org/documentation/additional/design/mediatype-video-raw.html?gi-language=c#formats from v210
format.