Template support for input parameters (#4)

This PR contains the work done to support input parameters for the `create` command of the executable target, and to render content dynamically for the newly-generated project.

Reviewed-on: #4
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>

Library/Resources/Files/Templates/App/App.mustache

@@ -0,0 +1,20 @@
+import AppLibrary
+import ArgumentParser
+
+@main
+struct App: AsyncParsableCommand {
+    
+    // MARK: Properties
+
+    @OptionGroup var options: Options
+    
+    // MARK: Functions
+
+    mutating func run() async throws {
+        let builder = AppBuilder(name: "{{ name }}")
+        let app = try await builder(options)
+
+        try await app.runService()
+    }
+
+}

Library/Resources/Files/Templates/Package.mustache

@@ -0,0 +1,45 @@
+// swift-tools-version:6.0
+
+import PackageDescription
+
+let package = Package(
+    name: "{{ name }}",
+    platforms: [
+        .macOS(.v14)
+    ],
+    products: [
+        .executable(name: "App", targets: ["App"]),
+        .library(name: "AppLibrary", targets: ["AppLibrary"])
+    ],
+    dependencies: [
+        .package(url: "https://github.com/hummingbird-project/hummingbird.git", from: "2.0.0"),
+        .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.3.0")
+    ],
+    targets: [
+        .executableTarget(
+            name: "App",
+            dependencies: [
+                .product(name: "ArgumentParser", package: "swift-argument-parser"),
+                .product(name: "Hummingbird", package: "hummingbird"),
+                .target(name: "AppLibrary")
+            ],
+            path: "App"
+        ),
+        .target(
+            name: "AppLibrary",
+            dependencies: [
+                .product(name: "ArgumentParser", package: "swift-argument-parser"),
+                .product(name: "Hummingbird", package: "hummingbird")
+            ],
+            path: "Library"
+        ),
+        .testTarget(
+            name: "AppTests",
+            dependencies: [
+                .product(name: "HummingbirdTesting", package: "hummingbird"),
+                .target(name: "AppLibrary")
+            ],
+            path: "Test"
+        )
+    ]
+)

Library/Resources/Files/Templates/Test/AppTests.mustache

@@ -0,0 +1,33 @@
+import AppLibrary
+import Hummingbird
+import HummingbirdTesting
+import Testing
+
+struct AppTests {
+
+    // MARK: Properties
+
+    private let arguments = TestArguments()
+    private let builder = AppBuilder(name: "{{ name }}")
+
+    // MARK: Route tests
+    
+    @Test(arguments: ["/"])
+    func routes(_ uri: String) async throws {
+        let app = try await builder(arguments)
+
+        try await app.test(.router) { client in
+            try await client.execute(uri: uri, method: .get) { response in
+                #expect(response.status == .ok)
+                #expect(response.body == .empty)
+            }
+        }
+    }
+
+}
+
+// MARK: ByteBuffer+Constants
+
+private extension ByteBuffer {
+    static let empty = ByteBuffer(string: "")
+}