DOC: Document FFMpegFileWriter *args, **kwargs

Adds documentation explaining that arguments are forwarded
to the parent MovieWriter class.

Fixes matplotlib#22831

Author: Saumya

lib/matplotlib/animation.py

@@ -611,13 +611,13 @@ class FFMpegFileWriter(FFMpegBase, FileMovieWriter):
     This effectively works as a slideshow input to ffmpeg with the fps passed as
     ``-framerate``, so see also `their notes on frame rates`_ for further details.
 
+    .. _their notes on frame rates: https://trac.ffmpeg.org/wiki/Slideshow#Framerates
+    
     Parameters
     ----------
     *args, **kwargs
         All arguments are forwarded to `FileMovieWriter`. See
         `FileMovieWriter` for a list of all possible parameters.
-
-    .. _their notes on frame rates: https://trac.ffmpeg.org/wiki/Slideshow#Framerates
     """
     supported_formats = ['png', 'jpeg', 'tiff', 'raw', 'rgba']