Feat(i18n) How to

Have an internationalized website is good but how ?

So I propose to use `react-intl` for message(thing wasn't write in markdown). 
But for markdown content I'm not sure on how to do.
For routing we will use next-config.

What you can do:

* Create an provider for the lang and message
Message should store on `i18n/locales/[locale].json`
* Creating lang switch component
