Add FAQ section

README.md

@@ -107,6 +107,56 @@ autocmd! User GoyoLeave nested call <SID>goyo_leave()
 More examples can be found here:
 [Customization](https://github.com/junegunn/goyo.vim/wiki/Customization)
 
+FAQ
+---
+
+> _"My custom colors are lost when I exit Goyo!"_
+
+That's because Goyo restores the base color scheme using `:colorscheme
+CURRENT_COLOR_SCHEME` command on exit, and it resets your tweaks. Goyo can try
+to remember all your customizations and restore them on exit, but it doesn't,
+because there is a better, more robust way to address the issue.
+
+The real problem here is that you will lose all your changes when you switch
+between color schemes, even when you're not using Goyo.
+
+```vim
+" In your Vim configuration file
+" - Base color scheme
+colorscheme molokai
+
+" - Your color customizations
+hi LineNr ctermfg=red guifg=red
+```
+
+It works, only when you stick to a single color scheme. When you switch
+between color schemes,
+
+```vim
+" Switch to another color scheme
+colorscheme Tomorrow-Night
+
+" Switch back to the original one
+colorscheme molokai
+```
+
+And all the customizations you have made are lost.
+
+What you should to do is to customize the colors on `autocmd ColorScheme`,
+which is automatically triggered whenever you change color schemes.
+
+```vim
+function! s:tweak_molokai_colors()
+  " Your molokai customizations
+  hi LineNr ...
+  hi FoldColumn ...
+endfunction
+
+autocmd! ColorScheme molokai call s:tweak_molokai_colors()
+
+colorscheme molokai
+```
+
 Inspiration
 -----------