fix(652): correct invalid frontmatter

[msmps]

Description

As part of my other pull request, I noticed some invalid frontmatter errors in the console.

Before vs After

[vercel[bot]]

@msmps is attempting to deploy a commit to the Syntax Team on Vercel.

A member of the Team first needs to authorize it.

[wesbos]

you rock! Also it seems the guest's name should be in black on dark mode. will need to fix that