Replace core team enumeration with link to the active core team

Replace core team enumeration with link to the active core team

We missed updating this when the core team changed a while ago, which
indicates that it's silly to have the same thing defined in more than
one place. Thus, replace it with a link.

Reviewed by both -core and funds-group.

As this does not contain any changes to the actual policy, this commit
does not bump the "last updated" date of the page.