doc: Update documentation in audio/ directory. * __get_properties__.m, audioplayer.m, disp.m, get.m, isplaying.m, pause.m, play.m, playblocking.m, resume.m, set.m, stop.m, subsasgn.m, subsref.m, __get_properties__.m, audiorecorder.m, disp.m, get.m, getaudiodata.m, getplayer.m, isrecording.m, pause.m, play.m, record.m, recordblocking.m, resume.m, set.m, stop.m, subsasgn.m, subsref.m, record.m, sound.m, soundsc.m: Re-write lots of documentation for clarity. Add @seealso links in @audioplayer and @audiorecorder classes.

--- a/scripts/audio/@audioplayer/subsasgn.m	Wed Dec 29 11:05:20 2021 -0800
+++ b/scripts/audio/@audioplayer/subsasgn.m	Wed Dec 29 18:17:53 2021 -0800
@@ -28,6 +28,7 @@
 ## Perform subscripted assignment on the audio player object @var{player}.
 ##
 ## Assign the value of @var{rhs} to the player property named by @var{idx}.
+## @seealso{@audioplayer/audioplayer}
 ## @end deftypefn
 
 function value = subsasgn (player, idx, rhs)