Multi-Language Manifest Support

[cbratschi]

Goals

1. the currently used manifest only support a single language
2. add support for multiple languages

Non-Goals

No response

Background

Manifests should be available in multiple languages. Otherwise multi-language websites can only use texts and URLs for a single language.

Current implementation:

https://nextjs.org/docs/app/api-reference/file-conventions/metadata/manifest

The W3C has a draft extension:

https://www.w3.org/TR/localizable-manifests/

Proposal

Support an interim solution until the official specs are supported by all major browser:

1. The best way would be to support https://www.w3.org/TR/localizable-manifests/#example-5 and split the manifest into separate file.
2. Add all manifest-.webmanifest to HTML head.