Doc: rewording of startify-autocmd

doc/startify.txt

@@ -647,11 +647,13 @@ $PWD and $OLDPWD are ignored.
 ==============================================================================
 AUTOCMD                                                       *startify-autocmd*
 
-In case you want to alter the startify buffer to cause all kinds of mayhem, an
-user autocmd is issued. You can hook into it like this:
+When the Startify buffer is fully set up, it emits an User event. You can hook
+into that to customize Startify even further:
 >
     autocmd User Startified let &l:stl = ' This statusline rocks!'
 <
+Or use it to disable single mappings: |startify-faq-16|.
+
 NOTE: Autocmds don't nest by default. If you use any command that triggers new
 events, be sure to add "nested": |autocmd-nested|.