Feature request: add multilingual functionalities to umami demo

I think this is a great aspiration.

It will be a lot of work, and we'd need to

1. identify which language we should use - we will need multiple volunteers who speak it as a first language who are also fluent enough in English to understand the existing content
2. adapt the content guidelines to the new language
3. translate enough of the content to make the translated version viable
4. translate the UI text
5. update the Umami configuration to support the second language
6. update the Umami install-time content import process to create the translated content
7. update the UI to incorporate language switching
8. ????
9. profit

I have no idea how we pick a language - I guess a good starting point is the community of volunteers who are happy to work on it initially and going forward. There have probably been approximately 30-40 or so people involved with the generation, review and refinement of the US English version so far.

I'd also suggest using another Left to Right (LTR) language would be a good first choice of additional language to keep this managable. No reason we can't add an RTL language after though!

Stray thought, but the easiest way to achieve this would be to have the second language be UK English. It wouldn't be as striking a demo but it would be the easiest way to achieve points 1-4 raised in #2.

I audited the site for translating everything, and aside of the two child issues I attached patches for (#2999893: Ensure umami views filter content by content negotiated language and #2999908: View more link in recipe cards is not fully translated), I didn't find any show stoppers for making this happen :-)

With those patches, I could fully translate the site using the Lingotek module and automatic translation.

Thank you so much @penyaskito! This is awesome ♥️

Note that https://www.drupal.org/project/multilingual_demo has a bunch of code to import translations of content items alongside the content items. It also uses CSV files, but would definitely need to be adapted.

Also this functionality will hopefully make that install profile obsolete and this feature bundled with core which is AMAZING.

For point 6 on the issue summary, would be nice to have #2931739: Bring migrate_source_csv to core.

I think the technical part and the translation part can run in parallel. Should we create issues for those?

Also found #2983573: Use migrate to build Umami content rather than bespoke code. which already takes care of that. Just so we don't overwork without adjusting priorities first.

All of these issues got resolved in #3028769: [META] Showcase Drupal's Multilingual Capabilities by implementing Umami in a 2nd language (Spanish)