Update runtime files.
diff --git a/runtime/doc/windows.txt b/runtime/doc/windows.txt
index 9a682e5..187d00e 100644
--- a/runtime/doc/windows.txt
+++ b/runtime/doc/windows.txt
@@ -1,4 +1,4 @@
-*windows.txt*   For Vim version 8.1.  Last change: 2019 May 05
+*windows.txt*   For Vim version 8.1.  Last change: 2019 May 18
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -1192,7 +1192,6 @@
 		the way when you're browsing code/text buffers.  The next three
 		commands also work like this.
 
-
 							*:sbn* *:sbnext*
 :[N]sbn[ext] [+cmd] [N]
 		Split window and go to [N]th next buffer in buffer list.