doc/filters: move fps filter start_time item to correct place

Fixes warnings
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

doc/filters.texi

@@ -4159,13 +4159,6 @@ round to nearest
 @end table
 The default is @code{near}.
 
-@end table
-
-Alternatively, the options can be specified as a flat string:
-@var{fps}[:@var{round}].
-
-See also the @ref{setpts} filter.
-
 @item start_time
 Assume the first PTS should be the given value, in seconds. This allows for
 padding/trimming at the start of stream. By default, no assumption is made
@@ -4174,6 +4167,13 @@ For example, this could be set to 0 to pad the beginning with duplicates of
 the first frame if a video stream starts after the audio stream or to trim any
 frames with a negative PTS.
 
+@end table
+
+Alternatively, the options can be specified as a flat string:
+@var{fps}[:@var{round}].
+
+See also the @ref{setpts} filter.
+
 @subsection Examples
 
 @itemize