Improve pullup documentation.

Mention that the fps filter should be used after pullup.

doc/filters.texi

@@ -6193,6 +6193,10 @@ its decisions. This filter is stateless in the sense that it does not lock
 onto a pattern to follow, but it instead looks forward to the following
 fields in order to identify matches and rebuild progressive frames.
 
+To produce content with an even framerate, insert the fps filter after
+pullup, use @code{fps=24000/1001} if the input frame rate is 29.97fps,
+@code{fps=24} for 30fps and the (rare) telecined 25fps input.
+
 The filter accepts the following options:
 
 @table @option
@@ -6235,6 +6239,11 @@ The main purpose of setting @option{mp} to a chroma plane is to reduce CPU
 load and make pullup usable in realtime on slow machines.
 @end table
 
+For example to inverse telecined NTSC input:
+@example
+-vf pullup,fps=24000/1001
+@end example
+
 @section removelogo
 
 Suppress a TV station logo, using an image file to determine which