doc: Sort the muxer documentation

Keep the sections alphabetically sorted.
doc: Name the MOV muxer as it should be called

The section name is the muxer, not the format.
hevc: Mention the missing SPS in the error message
hevc: Always consider VLC NALU type mismatch fatal

Sample-Id: 00001667-google
Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org