Updated Customization (markdown)

Customization.md

@@ -24,6 +24,30 @@ endfunction
 let g:goyo_callbacks = [function('Goyo_before'), function('Goyo_after')]
 ```
 
+## Quit Vim on `:q` if it's the only remaining buffer
+
+```vim
+function! GoyoBefore()
+  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! GoyoAfter()
+  " 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('GoyoBefore'), function('GoyoAfter')]
+```
+
 ## Disabling plugins
 
 ### MiniBufExpl with `g:miniBufExplBuffersNeeded` set