Bump markdown from 3.5.1 to 3.5.2

Bumps [markdown](https://github.com/Python-Markdown/markdown) from 3.5.1 to 3.5.2.
- [Release notes](https://github.com/Python-Markdown/markdown/releases)
- [Changelog](https://github.com/Python-Markdown/markdown/blob/master/docs/changelog.md)
- [Commits](Python-Markdown/markdown@3.5.1...3.5.2)

---
updated-dependencies:
- dependency-name: markdown
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -6,7 +6,7 @@ joblib==1.3.2
 jsmin==3.0.1
 livereload==2.6.3
 lunr==0.7.0.post1
-Markdown==3.5.1
+Markdown==3.5.2
 markdown-include==0.8.1
 MarkupSafe==2.1.3
 mkdocs==1.5.3