runtime(doc): fix some style issues and remove obsolete docs

Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index 3105a3d..8c79f56 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -1,4 +1,4 @@
-*builtin.txt*	For Vim version 9.1.  Last change: 2025 Jun 02
+*builtin.txt*	For Vim version 9.1.  Last change: 2025 Jun 07
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -2047,8 +2047,8 @@
 		  or empty string if no match was found or when using the
 		  default 'iskeyword' pattern.
 
-		When 'isexpand' is empty, uses the 'iskeyword' pattern
-		"\k\+$" to find the start of the current keyword.
+		When 'isexpand' is empty, uses the 'iskeyword' pattern "\k\+$"
+		to find the start of the current keyword.
 
 		Examples: >
 	set isexpand=.,->,/,/*,abc