new-account.sgml:

• Remove the requirement for mentors to send PGP keys of new committers to admins@.

committers-guide/article.sgml:

• Update copyright year.
• Emphasize that new committers should add their PGP key to the Handbook, since it might be needed for identification, e.g. for account recovery.

teams.ent:

• Add an entiry for admins@.

Discussed with: admins (joe, kensmith)