feat: a section about validating lean proofs

[nomeata]

No description provided.

[nomeata]

This is not quite how I want it to be yet::

• The CSS for changing the bullets for the “protection” list items is too unspecific. How can I add a CSS class around these lists only? Can I somehow set a CSS class in :::paragraph

• I think this section should have it’s own file, for easier linking to. But then, where to put it? You probably don’t want to remove htmlSplit := .never from the elaboration section?

I may need your help with these, @david-christiansen, and I assume there is some more polishing you’d like to see here.

[nomeata]

I figured out how to define a :::listBullet directive that locally changes the bullet. This seems at least somewhat reasonable to use here.

[david-christiansen]

for easier linking to

For linking, we can use the permalink feature. That'll also make sure the link never breaks even if we reorganize things later. If you right-click the chain links next to the header and do "copy link" then you'll get the permalink.

[nomeata]

Is this ready to be merged?

[github-actions]

Preview for this PR is ready! 🎉 (also as a proofreading version). built with commit 752f528.