patch 9.1.0211: page-wise scrolling does not support smooth-scrolling

Problem:  Page-wise scrolling with Ctrl-F/Ctrl-B implements
          it's own logic to change the topline and cursor.
          In doing so, skipcol is not handled properly for
          'smoothscroll', and virtual lines.
Solution: Re-use the logic from Ctrl-E/Ctrl-Y while staying
          backward compatible as much as possible.

closes: #14268

Signed-off-by: Luuk van Baal <luukvbaal@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index cd425b8..ff74970 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1,4 +1,4 @@
-*options.txt*	For Vim version 9.1.  Last change: 2024 Mar 25
+*options.txt*	For Vim version 9.1.  Last change: 2024 Mar 26
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -7502,8 +7502,8 @@
 	highlighted with |hl-NonText|.
 	You may also want to add "lastline" to the 'display' option to show as
 	much of the last line as possible.
-	NOTE: only partly implemented, currently works with CTRL-E, CTRL-Y
-	and scrolling with the mouse.
+	NOTE: only partly implemented, currently works with CTRL-E, CTRL-Y,
+	CTRL-B, CTRL-F and scrolling with the mouse.
 
 					*'softtabstop'* *'sts'*
 'softtabstop' 'sts'	number	(default 0)