Update runtime files.

runtime/doc/index.txt

@@ -1,4 +1,4 @@
-*index.txt*     For Vim version 8.2.  Last change: 2020 May 31
+*index.txt*     For Vim version 8.2.  Last change: 2020 Oct 05
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -784,10 +784,10 @@ tag		char	      note action in Normal mode	~
 				   lines down
 |gk|		gk		1  like "k", but when 'wrap' on go N screen
 				   lines up
-|gn|		gn	      1,2  find the next match with the last used
-				   search pattern and Visually select it
 |gm|		gm		1  go to character at middle of the screenline
 |gM|		gM		1  go to character at middle of the text line
+|gn|		gn	      1,2  find the next match with the last used
+				   search pattern and Visually select it
 |go|		go		1  cursor to byte N in the buffer
 |gp|		["x]gp		2  put the text [from register x] after the
 				   cursor N times, leave the cursor after it
@@ -1317,6 +1317,7 @@ tag		command		action ~
 |:filetype|	:filet[ype]	switch file type detection on/off
 |:filter|	:filt[er]	filter output of following command
 |:find|		:fin[d]		find file in 'path' and edit it
+|:final|	:final		declare an immutable variable in Vim9
 |:finally|	:fina[lly]	part of a :try command
 |:finish|	:fini[sh]	quit sourcing a Vim script
 |:first|	:fir[st]	go to the first file in the argument list
@@ -1691,6 +1692,7 @@ tag		command		action ~
 |:unsilent|	:uns[ilent]	run a command not silently
 |:update|	:up[date]	write buffer if modified
 |:vglobal|	:v[global]	execute commands for not matching lines
+|:var|		:var		variable declaration in Vim9
 |:version|	:ve[rsion]	print version number and other info
 |:verbose|	:verb[ose]	execute command with 'verbose' set
 |:vertical|	:vert[ical]	make following command split vertically