Change directory to nested Package.swift

[vknabel]

We had the same use as in #40.
We have a Package in ./BuildTools which includes Komondor among other tools.

To set up we run cd BuildTools && swift run komondor install. Though in the current master Komondor would head to the repositories' root and wouldn't find any Package.swift-file.

With this PR it would insert a simple cd ./BuildTools before looking for the manifest.
Therefore hooks will also be executed relative to the swift manifest.

---

An example of such a package in BuildTools/Package.swift:

// swift-tools-version:5.4
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: "BuildTools",
    platforms: [.macOS(.v10_11)],
    dependencies: [
        .package(url: "https://github.com/nicklockwood/SwiftFormat.git", from: "0.48.6"),
        .package(url: "https://github.com/shibapm/Komondor.git", from: "1.0.6"),
        .package(url: "https://github.com/realm/SwiftLint.git", from: "0.43.1"),
        .package(url: "https://github.com/SwiftGen/SwiftGen.git", from: "6.4.0")
    ],
    targets: []
)

#if canImport(PackageConfig)
    import PackageConfig

    let config = PackageConfiguration([
        "komondor": [
            "pre-commit": [
                "cd .. && swift run -c release --package-path BuildTools swiftgen",
                "cd .. && swift run -c release --package-path BuildTools swiftformat --config .swiftformat ./**/*.swift",
                "cd .. && swift run -c release --package-path BuildTools swiftlint autocorrect",
                "cd .. && git add ."
            ]
        ]
    ]).write()
#endif

[vknabel]

When trying to commit I receive an error:

Komondor/Tests/KomondorTests/KomondorTests.swift:1:18: error: no such module 'Komondor'
@testable import Komondor
                 ^
note: module 'Komondor' is the main module of an executable, and cannot be imported by tests and other targets

I could extract all code except main.swift into a separate target (e.g. KomondorKit) if you like.

[orta]

I like this strategy, I think it makes sense - thanks

[vknabel]

Thanks for the merge and all your work!

[orta]

I think @f-meloni might need to deploy, my swift build env seems to be real broken

[orta]

I did fix the dog pic in the README tho

[vknabel]

If I can take some work off you, just tell me.

[f-meloni]

I've released the version 1.1.0, let me know if everything is ok

[vknabel]

Thank you very much! The release works fine 👍
(Sorry for the late response – took some time off)