Lint: warn users about headers in divs in revealjs (was: Odd behavior in Print View)

Bug description

Hello there,

I am trying to print my revealjs presentation, but when I press E to enter Print View mode, two slide titles appear above my first slide and I can't print it.

My current workaround is to print only slides 3-21. Any idea on what is happening?

Steps to reproduce

Presentation: https://baarthur.github.io/29iioa_slides/src/iioa_slide.html#/title-slide
Code: https://github.com/baarthur/29iioa_slides/blob/main/src/iioa_slide.qmd

Expected behavior

No response

Actual behavior

No response

Your environment

No response

Quarto check output

[✓] Checking versions of quarto binary dependencies...
Pandoc version 3.1.2: OK
Dart Sass version 1.55.0: OK
NOTE: Deno version 1.33.2 is too old. Please upgrade to 1.33.1 or later.
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
Version: 1.4.60
Path: /Applications/quarto/bin

[✓] Checking basic markdown render....OK

[✓] Checking Python 3 installation....OK
Version: 3.9.6
Path: /Library/Developer/CommandLineTools/usr/bin/python3
Jupyter: (None)

  Jupyter is not available in this Python installation.
  Install with python3 -m pip install jupyter

[✓] Checking R installation...........OK
Version: 4.3.0
Path: /Library/Frameworks/R.framework/Resources
LibPaths:
- /Library/Frameworks/R.framework/Versions/4.3-arm64/Resources/library
knitr: 1.43
rmarkdown: 2.22

[✓] Checking Knitr engine render......OK

Start by reproducing the print view with the linked revealjs presentation and inspect the linked src/iioa_slide.qmd source, focusing on the headers that appear above the first slide. Done means the problematic header-in-div structure is identified and users receive a lint warning, while Print View no longer shows the unintended titles.