Bring back localized resources feature

[MrCsabaToth]

This was a feature of Hoverboard v1 what would be beneficial in my opinion. Or next DevFest will need at least English + Spanish version at the same time.

Unfortunately many people complain about difficulty of configuration. The v1 support had a problem that if the resources didn't match up perfectly with the default (if there were any missing translation), then the build failed. If the build procedure would survive that case I think it would not pose a roadblock for most people.

[ozasadnyy]

It's definitely on our roadmap but I don't know when it would be added. Any PRs would be appreciated ;)

[abraham]

This looks like a potentially great implementation.

https://github.com/andreasbm/lit-translate/

[MrCsabaToth]

For the records I looked it up and in Hoverboard v1 this functionality was provided by https://github.com/PolymerElements/app-localize-behavior

https://github.com/ValleyDevFest2016/valleydevfest/blob/master/bower.json#L10

[abraham]

Lit has a localization process now. https://lit.dev/docs/localization/overview/

[abraham]

Blocked until #796