This is probably not the best way to explain it, but it's short, and it works. Most people are using SVGs, so I don't want to devote a large amount of page space to it, so long as this is a single-page document.
Micro-benchmark results on my personal key.
$ gpg --export --export-options export-minimal '97225E589D6B9E01533C485EEC4B033C70096AD1' | wc -c
8118
$ gpg --export '97225E589D6B9E01533C485EEC4B033C70096AD1' | wc -c
78782
Realistically this only affects people (like me) who have a lot of signatures
on their key. But I think it's smart to document it the export-minimal way
to help those who do.
I am not sure where to place this, so far this is just the basics, and it's not linked to other pages yet. I've combined details from the Github wiki and the package.capnp file to create this, and it's possibly worded in a friendlier manner? Licenses should be broken out into a separate page, almost certainly. This still links to the Etherpad file as well as package.capnp as it is not as exhaustive, nor does it currently show formatting for the manifest. (I highly recommend spk init creates manifests with metadata fields ready to go. (See also: #787)