Allow you to choose the language of the website #61
Description
The website is currently in French.
However, since the green code initiative's objective is to operate internationally, it seems wise to pass it in English.
We could therefore propose a toggle button in the header to switch from English to French (the 2 languages supported now)
Default language: browser language or English
This also means planning for the internationalisation of the site: so, to set up an i18n management library and a file of label translations for each language.