Apple Support Starlark Modules and Rules

Apple Support provides a collection of Starlark helpers for rule authors targeting Apple Platforms (and Xcode) as well as some Rules directly.

Starlark Modules

`.bzl` file	Module
`@build_bazel_apple_support//lib:apple_support.bzl`	`apple_support`
`@build_bazel_apple_support//lib:xcode_support.bzl`	`xcode_support`

`.bzl` file	Rules
`@build_bazel_apple_support//rules:apple_genrule.bzl`	`apple_genrule`
`@build_bazel_apple_support//rules:toolchain_substitution.bzl`	`toolchain_substitution`
`@build_bazel_apple_support//rules:universal_binary.bzl`	`universal_binary`