Markdown is no longer supported in listings (>= 1.7.5)

[mcanouil]

Bug description

The addition of {=html} (to fix #11701) had an unfortunate and bad side effect which is that none of the field used in the default listings templates support markdown anymore.

5d6c846

Steps to reproduce

Using a simple website from quarto create project blog.
Modifying one of the post with:

---
title: "Welcome To My Blog with `code`"
description: |
  This is a text with **bold** and *italic* formatting.
author: "Tristan O'Malley"
date: "2024-12-27"
categories: [news]
---

This is the first post in a Quarto blog. Welcome!

![](thumbnail.jpg)

Since this post doesn't specify an explicit `image`, the first image in the post will be used in the listing page of posts.

Expected behavior

Any version up to 1.7.4

Actual behavior

From 1.7.5

Your environment

No response

Quarto check output

Quarto 99.9.9
[✓] Checking environment information...
      Quarto cache location: /Users/mcanouil/Library/Caches/quarto
[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.4.0: OK
      Dart Sass version 1.70.0: OK
      Deno version 1.46.3: OK
      Typst version 0.11.0: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 99.9.9
      commit: 241155a28bbfe8ffb5e9fd53f7396b516a7a8deb
      Path: /Users/mcanouil/Projects/quarto/quarto-cli/package/dist/bin

[✓] Checking tools....................OK
      TinyTeX: v2024.11
      Chromium: (not installed)

[✓] Checking LaTeX....................OK
      Using: TinyTex
      Path: /Users/mcanouil/Library/TinyTeX/bin/universal-darwin
      Version: 2024

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

[✓] Checking Python 3 installation....OK
      Version: 3.13.1
      Path: /Users/mcanouil/Projects/quarto/quarto-playground/.venv/bin/python3
      Jupyter: 5.7.2
      Kernels: julia-1.11, python3

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

(|) Checking R installation...........ℹ R version 4.4.2 (2024-10-31)
! Config '~/.Rprofile' was loaded!
[✓] Checking R installation...........OK
      Version: 4.4.2
      Path: /Library/Frameworks/R.framework/Resources
      LibPaths:
        - /Library/Frameworks/R.framework/Versions/4.4-arm64/Resources/library
      knitr: 1.46
      rmarkdown: 2.26

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