Then you should create a separate title page quarto document, put it as the first chapter, and move the preface to another document. The first document to appear in toc in the _quarto.yml file is considered as the "preface"

For all the #rstats people doing #AdventOfCode in R this year, here is a function to automatically get the data input for a challenge ! The SESSION is obtained from your cookies from the adventofcode.com website (see github.com/jonathanpaul...)