fdp-primer/writing-style: Refactor after adding new Vale rules

Over the last couple of day some new rules has been added, while some
rules have been replaced with the one from Vale builtin engines and some
have been removed.

• Update the fdp-primer to reflect those changes.
• As now there are mix of two different styles FreeBSD and Vale be more specific on naming those rules with dotted notation.
• Reword the rule FreeBSD.ConsciousLanguage by avoiding sensitive words itself.

Approved by: carlavilla (mentor)
Differential Revision: https://reviews.freebsd.org/D39800