patch 8.2.3227: 'virtualedit' can only be set globally

Problem:    'virtualedit' can only be set globally.
Solution:   Make 'virtualedit' global-local. (Gary Johnson, closes #8638)
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index e5a76b7..e0c14a8 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -8643,12 +8643,16 @@
 
 					    *'virtualedit'* *'ve'*
 'virtualedit' 've'	string	(default "")
-			global
+			global or local to buffer |global-local|
 	A comma separated list of these words:
 	    block	Allow virtual editing in Visual block mode.
 	    insert	Allow virtual editing in Insert mode.
 	    all		Allow virtual editing in all modes.
 	    onemore	Allow the cursor to move just past the end of the line
+	    none	When used as the local value, do not allow virtual
+			editing even when the global value is set.  When used
+			as the global value, "none" is the same as "".
+	    NONE	Alternative spelling of "none".
 
 	Virtual editing means that the cursor can be positioned where there is
 	no actual character.  This can be halfway into a tab or beyond the end