Bump plantuml-markdown from 3.5.2 to 3.5.3 in /config (#60)

Bumps [plantuml-markdown](https://github.com/mikitex70/plantuml-markdown) from 3.5.2 to 3.5.3.
- [Release notes](https://github.com/mikitex70/plantuml-markdown/releases)
- [Changelog](https://github.com/mikitex70/plantuml-markdown/blob/master/CHANGELOG.md)
- [Commits](mikitex70/plantuml-markdown@3.5.2...3.5.3)

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

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

config/requirements.txt

@@ -10,5 +10,5 @@ mkdocs-localsearch==0.9.1
 mkdocs-literate-nav==0.4.1
 mkdocs-jupyter==0.21.0
 
-plantuml-markdown==3.5.2
+plantuml-markdown==3.5.3
 markdown-include==0.6.0