Suggest new wording for section on exception safety

[dureuill]

• Describes the gamut of exception safety properties
• Introduces the concept of "intuitive exception safety" for sort algorithms, and explains why it is relevant
• Explains why not following intuitive exception safety may indirectly cause UB.

[Voultapher]

Thanks for creating the PR, I appreciate your help in improving the clarity of the text. Overall there a many good ideas in there, at the same time there are many small things, from using words like we and natural, to grammar things, concepts, language and tone, I have a bunch of suggestions that essentially end up in rewriting the thing, so that's what I did and pushed your branch with a new commit that can be inspected in isolation. Feel free to comment and or update it further.

[dureuill]

Sure your rewrite looks great to me, thanks for your time and patience 🙂