Update the technologies used:
* Update based on the use of the GitLab tracker instead of Bugzilla.
* Prefer security@eclipse-foundation.org instead of security@eclipse.org
* Clarify Security team naming, prefer Eclipse Foundation Security team
  to avoid confusion with other security teams that might exist in the
  future.

Additional clarifications and explanations.

Signed-off-by: Marta Rybczynska <marta.rybczynska@eclipse-foundation.org>