test: add test for embedded inline props

[QuentinRoy]

Description

Adds additional tests (currently failing) for embedded inline props such as:

::card
  Some sentence with non breaking spaces. A [link](./something.tar){download} with download inline props. sentence with non breaking spaces.
::

::card
  A [link](./something.tar){download} with download inline props. Another [link](./something.tar) without inline props.
::

Linked Issues

#10

[QuentinRoy]

@antfu, is there any pointers you could give me? I might be able to give it a crack when I have time, but I am not proficient with mdit.