SwiftGen SPM Plugin

This is temporary solution until SwiftGen implement it on their side. SwiftGen/SwiftGen#926

Usage

Package.swift

    dependencies: [
        .package(url: "https://github.com/drspoton/swiftgen-plugin-spm.git", .branch("main")),
    ],
    targets: [
        .target(
            name: "MyTarget",
            plugins: [
                .plugin(name: "SwiftGenPlugin", package: "SwiftGenPlugin")
            ]
        )
    ]

swiftgen.yml

output_dir: ${DERIVED_SOURCES_DIR}