Update runtime files
diff --git a/runtime/doc/index.txt b/runtime/doc/index.txt
index e5d29ad..2d96769 100644
--- a/runtime/doc/index.txt
+++ b/runtime/doc/index.txt
@@ -1,4 +1,4 @@
-*index.txt*     For Vim version 8.2.  Last change: 2021 Jan 15
+*index.txt*     For Vim version 8.2.  Last change: 2021 Feb 11
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -1176,6 +1176,7 @@
 |:bNext|	:bN[ext]	go to previous buffer in the buffer list
 |:ball|		:ba[ll]		open a window for each buffer in the buffer list
 |:badd|		:bad[d]		add buffer to the buffer list
+|:balt|		:balt		like ":badd" but also set the alternate file
 |:bdelete|	:bd[elete]	remove a buffer from the buffer list
 |:behave|	:be[have]	set mouse and selection behavior
 |:belowright|	:bel[owright]	make split window appear right or below