Add project-safe-transmute repository under automation

[Kobzol]

Repo: https://github.com/rust-lang/project-safe-transmute

Extracted from GH:

org = "rust-lang"
name = "project-safe-transmute"
description = "Project group working on the \"safe transmute\" feature"
bots = []

[access.teams]
compiler = "write"
libs-api = "write"
lang = "write"
wg-safe-transmute = "write"
security = "pull"
libs = "write"

[access.individuals]
thomcc = "write"
Mark-Simulacrum = "admin"
compiler-errors = "write"
oli-obk = "write"
petrochenkov = "write"
davidtwco = "write"
pietroalbini = "admin"
jdno = "admin"
nikomatsakis = "write"
Amanieu = "write"
joshtriplett = "write"
BurntSushi = "write"
nagisa = "write"
m-ou-se = "write"
wesleywiser = "write"
dtolnay = "write"
lcnr = "write"
rylev = "admin"
tmandry = "write"
jackh726 = "write"
pnkfelix = "write"
estebank = "write"
eddyb = "write"
Aaron1011 = "write"
michaelwoerister = "write"
matthewjasper = "write"
cuviper = "write"
the8472 = "write"
rust-lang-owner = "admin"
cjgillot = "write"
badboy = "admin"
scottmcm = "write"
jswrenn = "write"