Internationalization support

As a global community we have to recognize that a lot of members of our community do not speak or read English as a first language or at all. In order to support our members around the world and provide meaningful content to said members we must support internationalization. This can be achieved using [gettext](https://hexdocs.pm/gettext/Gettext.html).

The app needs to try and detect the locale of the request and redirect based on said locale. For example if the user's locale is Japanese then the user should be redirected to `/jp/`.

We should also provide a way for users to to choose a locale from a drop down member and/or be able to set their preferred locale which would be persisted in cookies and/or the database.