Revise Safety decision point value text

[ahouseholder]

• integrate safety impact changes into documentation #441 might be blocked by this issue

This issue is a breadcrumb from #479 to revisit the underlying issue in #380.

• Revise Safety Impact decision point for better integration with generated documentation #380 suggested revising the safety decision point to fit better in the generated documentation
• make safety table formats look better #479 took the approach of keeping the text while adding markdown and HTML formatting to the description strings to improve how it renders in the page

However, discussion within the team also raised the question of revising the actual decision point value descriptions so that they are less verbose. That seemed like more of a content revision effort, and so we made the choice to merge #479 and leave an issue behind (this one) to be addressed later with a content revamp.

[ahouseholder]

Depending on how/when this issue is resolved, issue #483 might be made redunant.