Oh sed. Never change; I love you.

1{ /^\[endpoint\]/ {
        N
        s/.*/endpoints = {\n\n"admin\/login": {/
 }
}
$a"""\n}\n}
s/\[curl\]/"curl": """/
s/\[headers\]/""",\n\n"headers":"""/
/"curl"/,/"headers"/ {
        /^$/d
}
s/\[body\]/""",\n\n"body":"""/
/"headers"/,/"body"/ {
        /^$/d
}
/\[endpoint\]/,+1 {
        s/\[endpoint\]/"""\n  },\n/
        s/^\([a-z].*\)$/"\1" : {/
}
/"body"/,/"""/{
        /^$/d
}