patch 9.1.0418: Cannot move to previous/next rare word

Problem:  Cannot move to previous/next rare word
          (Colin Kennedy)
Solution: Add the ]r and [r motions (Christ van Willegen)

fixes: #14773
closes: #14780

Signed-off-by: Christ van Willegen - van Noort <github.com@vanwillegen-vannoort.nl>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/spell.txt b/runtime/doc/spell.txt
index ab3b120..809e3a8 100644
--- a/runtime/doc/spell.txt
+++ b/runtime/doc/spell.txt
@@ -1,4 +1,4 @@
-*spell.txt*	For Vim version 9.1.  Last change: 2024 May 11
+*spell.txt*	For Vim version 9.1.  Last change: 2024 May 17
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -62,6 +62,17 @@
 							*[S*
 [S			Like "]S" but search backwards.
 
+							*]r*
+]r			Move to next "rare" word after the cursor.
+			A count before the command can be used to repeat.
+			'wrapscan' applies.
+
+							*[r*
+[r			Like "]r" but search backwards, find the "rare"
+			word before the cursor.  Doesn't recognize words
+			split over two lines, thus may stop at words that are
+			not highlighted as rare.
+
 
 To add words to your own word list: