cc-ssh-key-list: too much spacing below the first section

[florian-sanders-cc]

Context

In the first section of the cc-ssh-key-list component, we show text to help people generate their SSH key.

This text is implemented using paragraphs but the last paragraph adds a spacing below that makes the spacing of the first section bigger than typical cc-block-section.

This should be easy to fix:

• either remove all paragraph margins & use display: grid + gap: 0.5em on their parent,
• or only set margin-bottom for paragraphs that are not the last with the :not(:last-of-type) selector.