React-intl example

[sedubois]

I saw some people wondering how to get react-intl working with Next.js, and so far it worked well in my app: https://github.com/relatenow/relate

So maybe it could be used as inspiration to create an example in the examples folder.

[sedubois]

Also see @ericf's WIP example which does a better job of loading only the active locale client-side: formatjs/formatjs#844

[ericf]

I completed the example. This is my first time really digging into Next, so it would be great to get a review here: formatjs/formatjs#844

Also I'm happy to move this example app to this repo. Or if we decide to leave it in React Intl's repo, it would be nice to add least add an examples/react-intl/README.md entry here.

[timneutkens]

@ericf looks good! I'd love to have this in the next.js repo 👍🏻👍🏻

[ericf]

@timneutkens @sedubois I opened PR #1055 to add it here.

[julkue]

The example is broken: #3386 (comment)