Add i18n

[Valefant]

For now we will support: English, German and Italian (sry I don't know any more languages than that 😓)

Implementation Note

For the client side localization we will use the following library
https://github.com/ivanhofer/typesafe-i18n (Typesafety ftw! 😎 )

For the flags we will use the following svg files
https://github.com/lipis/flag-icons/tree/main/flags/1x1

Save the selected locale in locale storage. If none is available, set English as default language

General Note

Link the flag providing repository in our README.md under the Resources section