The origins of this one were a good example of the XY problem.

User request:
> How do I make an aside with a custom icon?

After some back and forth it turned out that the real request was:
> How can I style some content but use the :::aside syntax supported in Starlight?

They enjoyed that authoring experience for styled blocks. That authoring experience was only available for asides. Therefore they must want asides!

This plugin does make custom asides easy, but you can also do much more. Maybe you want :::figure or :::lede blocks or some other markup, all from the comfort of your .md file.