administration: liaison, Bugmeister and a little more

Some texts use the shortened team ID for team liaison roles, other texts
use the plain English team name. Recent 2293645 is plain – Core Team
Liaison – so, for consistency, be plain elsewhere.

Bugmeister should be singular. Consistent with
https://wiki.freebsd.org/Bugmeister – see this month's editions to the
page.

Correct a typo (ThePorts).

Minor improvements to the section for the Donations Team.

Reviewed by: carlavilla dbaio gahr linimon rene
Differential Revision: https://reviews.freebsd.org/D37213