When you set your .target() up in your .targets[] in
SPM you dont specifiy a path, it will look at [PackageRoot]/Sources/[TargetName] but if you are doing something different, you can specify that path with .target(path: "PathToSource")
path: The custom path for the target. By default, the Swift Package Manager requires a target's sources to reside at predefined search paths; for example, `[PackageRoot]/Sources/[TargetName]`. Don't escape the package root; for example, values like `../Foo` or `/Foo` are invalid.
You can also do a mega package by specifying just Sources as the path.