Update proposals/0264-stdlib-preview-package.md
Update proposals/0264-stdlib-preview-package.md

Co-Authored-By: Ben Rimmington <b1c1d8736f20db3fb6c1c66bb1455ed43909f0d8@benrimmington.com>
apple/swift-evolution,apple/swift-evolution,abertelrud/swift-evolution,abertelrud/swift-evolution,hartbit/swift-evolution,hartbit/swift-evolution,natecook1000/swift-evolution,natecook1000/swift-evolution