Docs suggestion: guide to where things go in the .yml file

[jtr13]

Description

I've been struggling a big figuring out where options go in the .yml -- for example on this page https://quarto.org/docs/reference/formats/html.html there is a complete list of options but it's not always clear which key the options should go under. I've been mainly looking at examples to figure it out.

[jtr13]

Also discussed in the following issues:

#5186 (book: vs format: options)

#4315 (fig-align doesn't work in html: format:)

#3371 (knitr: opts_chunk: takes . format)

[mcanouil]

(Changing this to Feature Requests)

[cwickham]

Linking to Reference Improvement issue: #5187

[mcanouil]

Closing in favour of #5187