The formal title of the muxer according to the specification
is "RCWT (Raw Captions With Time)", so canonize this
in the long name of the codec and docs.

In the documentation section, point #2 was wrong: ccextractor
extracts the Closed Captions data and stores normalized bits
similarly to this muxer.
Signed-off-by: Marth64 <marth64@proxyid.net>