MD -> LaTeX: `imports` not accessible to

[LecrisUT]

One would expect to be able to add to the list of package imports via

exports:
  - format: pdf+tex
    imports:
      - physics

But this currently has no effect. Of course this is not complete since the imports could have additional options, but this should fix basic \usepackage needs

[LecrisUT]

There seems to be more nuance to this, because even if we include the missing \usepackage, myst will still complain of Undefined control sequence:

[jan-david-fischbach]

:+1: Any Progress on this?