Importing LLVM c++ into swift package

Hey all I am pretty new to using c++ interop. I am trying to import the system LLVM headers into a swift package for a project, but can't seem to find any instructions on how to do so. The official c++ / swift interop docs shows a very basic example of how to add a c++ library to the project, but I'm not sure how that would translate to a system library such as LLVM. I tried using a version installed LLVM via Homebrew, but I got the message

For compilers to find llvm you may need to set:
export LDFLAGS="-L/opt/homebrew/opt/llvm/lib"
export CPPFLAGS="-I/opt/homebrew/opt/llvm/include"

Do these flags need to be in the package.swift manifest? Or should I not be using a Homebrew version of LLVM?

I'm still having some trouble, specifically getting SPM to automatically generate the module map. I think I'm doing something wrong. My package structure looks like this:

├── Package.swift
├── Sources/
│   └── MyTarget/
│       └── main.swift
├── include/
│   └── llvm/
│       ├── Module.h -> /opt/homebrew/opt/llvm/include/llvm/IR/Module.h
│       ├── LLVMContext.h -> /opt/homebrew/opt/llvm/include/llvm/IR/LLVMContext.h
│       └── raw_ostream.h -> /opt/homebrew/opt/llvm/include/llvm/Support/raw_ostream.h

And my package.swift looks like this:

// swift-tools-version: 5.10
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: "MyProject",
    targets: [
            name: "MyTarget",
            publicHeadersPath: "include"

And when I try to:

import llvm

In main.swift, I get:

No such module 'llvm'

Does this all look right? Do I need to set a path somewhere else because I am using the Homebrew LLVM headers?