internal/about: update URLs for providers

https://github.com/freebsd/freebsd-doc/pull/155
corrected use of uppercase for NIC.br and for Your.Org.

https://github.com/freebsd/freebsd-doc/pull/156
found a working alternative to a page that is no longer reachable; and
English alternatives to two Japanese pages.

Other minor changes, to make internal/about consistent with the status
report that is changed by PRs 155 and 156.

Approved by: dbaio
Pull request: https://github.com/freebsd/freebsd-doc/pull/157