Add i18n documentation

[alexgagnon]

Prerequisites

• [X] I have read the Contributing Guidelines.
• [X] I agree to follow the Code of Conduct.
• [X] I have searched for existing issues that already include this feature request, without success.

Describe the Feature Request

Hi, I've been looking at adopting Stencil to create primitives for our design system, but I'm struggling to find information on best-practices for i18n (a must for our system). I notice LitElement just shipped an officially supported i18n package (https://lit.dev/docs/localization/overview/), is there something similar in the works for Stencil? Or if there's already a solution in place, would it be possible to put some documentation under Guides?

Describe the Use Case

Be able to ship i18n-ready components

Describe Preferred Solution

Something officially supported by the StencilJS team, or at least a document with best-practices

Describe Alternatives

No response

Related Code

No response

Additional Information

No response

[dmartinjs]

At work, we are using Polyglot.

But I referenced the libs, I saw in most exemples in articles.

I'll write an exemple here and provide a PR for the documentation to help newcomers.

[splitinfinities]

I'm going to move this to the Stencil Site repo, actually! This can be documented best there.