Updated Customization (markdown)

Customization.md

@@ -77,14 +77,20 @@ Suggested by [mm2703](https://github.com/mm2703) and [axelGschaider](https://git
 ```vim
 function! g:goyo_before()
   let b:quitting = 0
+  let b:quitting_bang = 0
   autocmd QuitPre <buffer> let b:quitting = 1
+  cabbrev <buffer> q! let b:quitting_bang = 1 <bar> q!
 endfunction
 
 function! g:goyo_after()
   " Quit Vim if this is the only remaining buffer
   if b:quitting && len(filter(range(1, bufnr('$')), 'buflisted(v:val)')) == 1
+    if b:quitting_bang
+      qa!
+    else
       qa
     endif
+  endif
 endfunction
 
 let g:goyo_callbacks = [function('g:goyo_before'), function('g:goyo_after')]