patch 8.2.3555: ModeChanged is not triggered on every mode change

Problem:    ModeChanged is not triggered on every mode change.
Solution:   Also trigger on minor mode changes. (Maguns Gross, closes #8999)
diff --git a/runtime/doc/autocmd.txt b/runtime/doc/autocmd.txt
index bcc81ec..6a4edf9 100644
--- a/runtime/doc/autocmd.txt
+++ b/runtime/doc/autocmd.txt
@@ -930,18 +930,23 @@
 							*ModeChanged*
 ModeChanged			After changing the mode. The pattern is
 				matched against `'old_mode:new_mode'`, for
-				example match against `i:*` to simulate
-				|InsertLeave|.
+				example match against `*:c*` to simulate
+				|CmdlineEnter|.
 				The following values of |v:event| are set:
 				   old_mode	The mode before it changed.
 				   new_mode	The new mode as also returned
-						by |mode()|.
+						by |mode()| called with a
+						non-zero argument.
 				When ModeChanged is triggered, old_mode will
 				have the value of new_mode when the event was
 				last triggered.
+				This will be triggered on every minor mode
+				change.
 				Usage example to use relative line numbers
 				when entering Visual mode: >
-	:autocmd ModeChanged *:v set relativenumber
+	:au ModeChanged [vV\x16]*:* let &l:rnu = mode() =~# '^[vV\x16]'
+	:au ModeChanged *:[vV\x16]* let &l:rnu = mode() =~# '^[vV\x16]'
+	:au WinEnter,WinLeave * let &l:rnu = mode() =~# '^[vV\x16]'
 <							*OptionSet*
 OptionSet			After setting an option.  The pattern is
 				matched against the long option name.