porters-handbook/versions: Pet vale

• Find the terms that are only used once in our entire doc set and mark those with back ticks so they are not marked as spelling mistakes by Vale
• Reduce pronouns usage and change accordingly
• Use Conscious language
• Fix spelling mistakes
• Fix repeated words
• Fix EOL Spaces
• Reduce contractions
• Bypass Vale.Terms rule in 3 cases where it should be written as freebsd instead of FreeBSD

Approved by: bcr (mentor)
Differential Revision: https://reviews.freebsd.org/D40080