doc/filters: remove aconvert

Signed-off-by: Paul B Mahol <onemda@gmail.com>

doc/filters.texi

@@ -309,41 +309,6 @@ build.
 
 Below is a description of the currently available audio filters.
 
-@section aconvert
-
-Convert the input audio format to the specified formats.
-
-@emph{This filter is deprecated. Use @ref{aformat} instead.}
-
-The filter accepts a string of the form:
-"@var{sample_format}:@var{channel_layout}".
-
-@var{sample_format} specifies the sample format, and can be a string or the
-corresponding numeric value defined in @file{libavutil/samplefmt.h}. Use 'p'
-suffix for a planar sample format.
-
-@var{channel_layout} specifies the channel layout, and can be a string
-or the corresponding number value defined in @file{libavutil/channel_layout.h}.
-
-The special parameter "auto", signifies that the filter will
-automatically select the output format depending on the output filter.
-
-@subsection Examples
-
-@itemize
-@item
-Convert input to float, planar, stereo:
-@example
-aconvert=fltp:stereo
-@end example
-
-@item
-Convert input to unsigned 8-bit, automatically select out channel layout:
-@example
-aconvert=u8:auto
-@end example
-@end itemize
-
 @section adelay
 
 Delay one or more audio channels.