/concepts/flakes: add tables comparing alternatives #1212
Description
currently, /concepts/flakes lists pros/cons/alternatives for some stages of flake usage.
while some alternatives may specifically address specific cons without being mutually exclusive with other options, overall this current structure leaves a lot of information out, essentially leaving readers guessing which alternatives resolves which drawbacks (and perhaps at what cost of their own).
a way to address this would be to for each of these sections add proper comparison tables, so that readers would have a better overview of the different options available.