Add learner profiles

[adamancer]

The Learner Profiles link in the top bar of the lesson currently resolves to a placeholder file. The definition for the placeholder file is not very informative, but here are some Carpentries resources we can base the profiles on:

• https://cdh.carpentries.org/deciding-what-to-teach.html#learner-profiles
• https://software-carpentry.org/audience/
• https://teaching-programming.netlify.app/personas/
• https://carpentries-incubator.github.io/good-enough-practices/learner-profiles/index.html

This seems to be a common issue with the new sandpaper lessons. I checked a few lessons I've used in the past and they all still have the placeholder up.