Improve citation section

[orzechow]

This collapses all but one citation for better appearance.
It also adds my thesis to the citations.

Based on #81, refined and rebased onto main.

#patch

[ll-nick]

Great, thanks!

I'm still in favor of a subtle horizontal separation of the publications using --- as proposed in #81.
But if you don't like those, feel free to merge without those. I guess that's a matter of taste.

[orzechow]

I'm still in favor of a subtle horizontal separation of the publications using --- as proposed in #81. But if you don't like those, feel free to merge without those. I guess that's a matter of taste.

Oh sorry, I missed that.

It's a good idea, though these horizontal lines are a bit off in horizontal spacing IMHO.
How about subheadings like in 1c2b26a?

[ll-nick]

Yup, that works too 👍