Add a language switch

[phiter]

Feature Description

Add internationalization to the project and allow the user to switch between different languages (maybe a dropdown in the appbar).

Problem

Matrix is growing in usage, specially now with lots of people working from home, and some of these people might not know english, so it would be great if they could use the application in a language they are familiar with.

Proposed solution

We can add a i18n library for the react application and extract all current texts to a language file, and add another language. The .variables file could also have a default language set by the system administrator.

Additional comments

Since this project was created by a brazilian company and many of our users are brazilian, I believe we could benefit from having both english and portuguese translations at first, and then add more later.

The project is still small so the sooner we add i18n, the easier it will be in the future.

[juliemar]

Hi @phiter could you open a PR with the internationalization inside rooms?

[phiter]

Hey @juliemar I took some time off open source for now in order to better focus on my new job. I'll come back later but you guys can work out on the branch that I made that already contains everything.