Document how to correctly use i18n translations in JS modules

[baptistegrimaud]

Description

Write a dedicate section/page about how internalization should be used within JavaScript modules, in particular when components from different modules are used on the same page.

For now, we only have this comment:

javascript-modules/javascript-create-module/templates/hello-world/src/components/Hello/World/Celebrate.client.tsx

Line 16 in ebc52f7

// IMPORTANT: Always use useTranslation() (not { t } from "i18next") in React components.

TL;DR

In short, we should always use:

import { useTranslation } from "react-i18next";
...
const { t } = useTranslation();
...
<p>{t("my-key")}</p>

For both client and server code.