Add github-callouts markdown extension

This allows us to use [GitHub Alerts] in our markdown files, so
admonitions can render nicely on GitHub too.

[GitHub Alerts]: https://docs.github.com/en/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax#alerts

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

mkdocs.yml

@@ -68,6 +68,7 @@ markdown_extensions:
   - attr_list
   - def_list
   - footnotes
+  - github-callouts
   - markdown_svgbob:
       min_char_width: 0
   - pymdownx.details

pyproject.toml

@@ -48,6 +48,7 @@ dev-mkdocs = [
   "Markdown == 3.5.2",
   "black == 24.2.0",
   "frequenz-repo-config[lib] == 0.9.1",
+  "markdown-callouts == 0.4.0",
   "markdown-svgbob == 202112.1022",
   "mike == 2.0.0",
   "mkdocs-gen-files == 0.5.0",