Extend I18N/L10N to include support for languages and especially cultures

[aphillips]

Section 2.4 The web is for all people
https://www.w3.org/TR/2024/DNOTE-ethical-web-principles-20240319/#allpeople

We will build internationalization and localization capabilities into our specifications and websites.

This is gratifying to see, but I18N thinks is should be amended a bit. We think it should include support for different languages and for a diversity of cultures, including not disadvantaging smaller language or cultural communities.

NOTE WELL: @plehegar This repo lacks horizontal review labels. This issue should have an i18n-needs-resolution label.

[torgo]

Thanks @aphillips ! We'll have a look at this soon and come back to you with any proposed changes.