Added reproducibility introduction

[vtraag]

Hi @PetrosStav and @xpapag, I've now added the introduction to the reproducibility part that you wrote earlier. However, I'm not sure if this is really becoming clear. That is, in the Quarto structure, I cannot add text separate from any chapter, and so hence, it needs to be in some chapter. However, you then get something like this in the table of contents:

This doesn't seem to make clear it's really an introduction of some sorts. Would you be OK with just renaming the chapter to "Introduction to Reproducibility"?

Let me know if you want to make any other changes,

[vtraag]

Ping @PetrosStav and @xpapag.

[vtraag]

@PetrosStav and @xpapag, I've now changed the title and updated the authors. I'll merge tomorrow unless you need to make any changes still.