Integrating yasumi library

Hi,
I think it would be interesting to integrate the yasumi library www.yasumi.dev/docs/providers/ for automatic holiday import and integration with the standard calendars.

By pushing the integration a little more, it is unimaginable to define the country of each person or team and thus define the holidays per person or per team for the different calculations of availability, resource allocation, ...
Especially interesting when the teams are spread over several countries or regions.