status: 2023q1: Core Team: clarity, consistency

Clarfy one sentence, in response to ceri@ at
https://lists.freebsd.org/archives/dev-commits-doc-all/2023-March/001806.html

Whilst here:

• first and third items use the phrase 'Core Team', the second item might reasonably do the same

• where the fourth item uses shorter phrases 'Core', 'src' and 'source', source can be shortened to src.

Approved by: carlavilla (core secretary), status (salvadore)
Pull request: https://github.com/freebsd/freebsd-doc/pull/147