Add adobe/remark-gridtables

[benabel]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and discussions and couldn’t find anything or linked relevant results below
• I made sure the docs are up to date
• I included tests (or that’s not needed)

Description of changes

This package is compatible with new versions of remark.

[github-actions]

Hi! It seems you removed the template which we require. Here are our templates (pick the one you want to use and click *raw* to see its source):

• pull-request-template.md

I won’t send you any further notifications about this, but I’ll keep on updating this comment, and hide it when done!

Thanks,
— bb