Add generate-manifest-list repository under automation

[Kobzol]

Repo: https://github.com/rust-lang/generate-manifest-list

Extracted from GH:

org = "rust-lang"
name = "generate-manifest-list"
description = "Creates a list of manifests on static.rust-lang.org"
bots = []

[access.teams]
security = "pull"

[access.individuals]
pietroalbini = "admin"
Mark-Simulacrum = "admin"
rust-lang-owner = "admin"
rylev = "admin"
badboy = "admin"
jdno = "admin"

[Kobzol]

I defaulted to the suggestion from https://hackmd.io/@rust-leadership-council/Bk6ge9Xu6, as usually :) Do you want opinion from others, e.g. Mark on this?

[rylev]

Yea. What are your thoughts @Mark-Simulacrum, @pietroalbini, or @jdno

[jdno]

I don't have context here, so I defer to @Mark-Simulacrum's opinion.

[Mark-Simulacrum]

I'm comfortable expanding the access. I confirmed the token available to generate-manifest-list can't write to anything except the manifests list.