runtime(doc): document further keys that scroll page up/down

fixes: #15107

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/scroll.txt b/runtime/doc/scroll.txt
index cf79353..b88e27b 100644
--- a/runtime/doc/scroll.txt
+++ b/runtime/doc/scroll.txt
@@ -1,4 +1,4 @@
-*scroll.txt*    For Vim version 9.1.  Last change: 2022 Oct 17
+*scroll.txt*    For Vim version 9.1.  Last change: 2024 Jul 05
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -48,6 +48,8 @@
 
 <S-Down>	or				*<S-Down>* *<kPageDown>*
 <PageDown>	or				*<PageDown>* *CTRL-F*
+<S-CR>	or				*<S-CR>* *CTRL-SHIFT-CR* *<S-NL>*
+<S-+>	or					*SHIFT-+* *<S-Plus>*
 CTRL-F			Scroll window [count] pages Forwards (downwards) in
 			the buffer.  See also 'startofline' option.
 			When there is only one window the 'window' option
@@ -85,6 +87,7 @@
 
 <S-Up>		or					*<S-Up>* *<kPageUp>*
 <PageUp>	or					*<PageUp>* *CTRL-B*
+<S-->		or				*<S-Minus>* *SHIFT-MINUS*
 CTRL-B			Scroll window [count] pages Backwards (upwards) in the
 			buffer.  See also 'startofline' option.
 			When there is only one window the 'window' option