replace flags with GitHub markdown emoji markup

README.md

@@ -4,11 +4,11 @@
 
 ## Translations
 
-- [🇨🇳 Chinese version](https://github.com/glepnir/nvim-lua-guide-zh)
-- [🇪🇸 Spanish version](https://github.com/RicardoRien/nvim-lua-guide/blob/master/README.esp.md)
-- [🇧🇷 Portuguese version](https://github.com/npxbr/nvim-lua-guide/blob/master/README.pt-br.md)
-- [🇯🇵 Japanese version](https://github.com/willelz/nvim-lua-guide-ja/blob/master/README.ja.md)
-- [🇷🇺 Russian version](https://github.com/kuator/nvim-lua-guide-ru)
+- [:cn: Chinese version](https://github.com/glepnir/nvim-lua-guide-zh)
+- [:es: Spanish version](https://github.com/RicardoRien/nvim-lua-guide/blob/master/README.esp.md)
+- [:brazil: Portuguese version](https://github.com/npxbr/nvim-lua-guide/blob/master/README.pt-br.md)
+- [:jp: Japanese version](https://github.com/willelz/nvim-lua-guide-ja/blob/master/README.ja.md)
+- [:ru: Russian version](https://github.com/kuator/nvim-lua-guide-ru)
 
 ## Introduction