patch 9.1.1426: completion: register contents not completed

Problem:  CTRL-X CTRL-R only completes individual words from registers,
          making it difficult to insert complete register content.
Solution: Add consecutive CTRL-X CTRL-R support - first press completes
          words, second press completes full register lines, similar to
          CTRL-X CTRL-L and CTRL-X CTRL-P behavior (glepnir).

closes: #17395

Signed-off-by: glepnir <glephunter@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/usr_24.txt b/runtime/doc/usr_24.txt
index 250bd17..0f72495 100644
--- a/runtime/doc/usr_24.txt
+++ b/runtime/doc/usr_24.txt
@@ -1,4 +1,4 @@
-*usr_24.txt*	For Vim version 9.1.  Last change: 2018 Mar 18
+*usr_24.txt*	For Vim version 9.1.  Last change: 2025 Jun 02
 
 		     VIM USER MANUAL - by Bram Moolenaar
 
@@ -187,7 +187,7 @@
 	CTRL-X CTRL-D		macro definitions (also in included files)
 	CTRL-X CTRL-I		current and included files
 	CTRL-X CTRL-K		words from a dictionary
-	CTRL-X CTRL-R		words from registers
+	CTRL-X CTRL-R		contents from registers
 	CTRL-X CTRL-T		words from a thesaurus
 	CTRL-X CTRL-]		tags
 	CTRL-X CTRL-V		Vim command line