doc/encoders: fix broken build with 884506dfe2

doc/encoders.texi

@@ -1200,26 +1200,26 @@ Same as @samp{3}, but with extra processing enabled.
 @end table
 @end table
 
- at anchor{mjpegenc}
- at section mjpeg
+@anchor{mjpegenc}
+@section mjpeg
 
 Motion JPEG encoder.
 
- at subsection Options
+@subsection Options
 
- at table @option
- at item huffman
+@table @option
+@item huffman
 Set the huffman encoding strategy. Possible values:
 
- at table @samp
- at item default
+@table @samp
+@item default
 Use the default huffman tables. This is the default strategy.
 
- at item optimal
+@item optimal
 Compute and use optimal huffman tables.
 
- at end table
- at end table
+@end table
+@end table
 
 @anchor{wavpackenc}
 @section wavpack