Fixup CVE

[todb]

Cleaned up the CVE page a little in prep for publishing some advisories that have been made public.

• Adds a useful "expand" javascript-basted button, that more or less works. If you have a better method to create expandable sections, feel free to offer those after landing this one.
• Fix up some of the intro language to the CVE page to describe what VDPs are, and be clearer about our CVE-assignment.

You'll note I haven't updated the Reserved CVEs section. Since we're looking to move to another publishing platform (See #148), I won't put a ton of work into that, but once this lands, I'll fill that out, along with revealing our first public CVEs.

[todb]

Also, I tested locally. Looks like this:

Note the "expand" button disappears once expanded. Kinda lame but also who cares.

[todb]

Added our reserved CVEs, but the table formatting is garbage and I don't really care.

[mauvehed]

It's good enough.