use 'front-matter' for parsing front matter

[swyxio]

Describe the bug

generate_docs uses site-kit, which uses a homecooked front matter parser. however this is non standard frontmatter:

this:

title: "Scooby Doo: Where are you"
published: false

should parse to:

{
	"title": "Scooby Doo: Where are you",
	"published": false
}

whereas with site-kit this happens:

{
	"title": "\"Scooby Doo: Where are you\"",
	"published": "false"
}

which causes nasty bugs down the line.

front-matter exists, we should use and encourage it.

i dont know if a formal frontmatter spec exists, but from experience this behavior is fairly standard now.

if you accept this i am happy to submit a PR but i am holding off because i'm sensing a PR backlog.