doc/muxers: document which applications are known to need disable_chpl.

Thanks to: John Stebbins <stebbins@jetheaddev.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

doc/muxers.texi

@@ -555,7 +555,8 @@ Add RTP hinting tracks to the output file.
 Disable Nero chapter markers (chpl atom).  Normally, both Nero chapters
 and a QuickTime chapter track are written to the file. With this option
 set, only the QuickTime chapter track will be written. Nero chapters can
-cause failures when the file is reprocessed with certain tagging programs.
+cause failures when the file is reprocessed with certain tagging programs, like
+mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
 @end table
 
 @subsection Example