Add a discussion of philosophical underpinnings of SBC

[martinmodrak]

Inspired by this comment: https://statmodeling.stat.columbia.edu/2021/09/03/simulation-based-calibration-some-challenges-and-directions-for-future-research/#comment-2022628

The goal would be to document somewhere some of the philosphical moves behind SBC. So far not sure where would be best, but it would probably be useful at some point.

[hyunjimoon]

I have tweaked some investigation on calibration here. Including in that very document or adding a separate wiki page seems to be the best option.

[martinmodrak]

Partially addressed in acfd50fab2193ff96463d5af6bcae7c20d2951c1