Admonition support

[thim81]

Describe your feature request

I'm a big fan of Marktext and it has become my default Markdown editor.
I'm using it mostly to write documentation, which works really well.

To create user-friendly documentation, I use the full spectrum of the markdown markup.
I like to use "highlights" to make warnings/tips/... stand-out.
For this I'm using the "Admonition" markdown addition.
https://python-markdown.github.io/extensions/admonition/

It would be really great that MarkText supports this; visually or at minimum support the "indented by four spaces", which I can't seem to get working.

What problem does this feature solve? [optional]

Support visual rending of the "Admonition" markdown format.

Additional context [optional]

Have a look at some visual examples:
https://squidfunk.github.io/mkdocs-material/extensions/admonition/#note