Implemented the initialization functions for the DocCMiddleware type in the library target.

Sources/DocCMiddleware/Public/Middlewares/DocCMiddleware.swift

@@ -0,0 +1,61 @@
+// ===----------------------------------------------------------------------===
+//
+// This source file is part of the Hummingbird DocC Middleware open source project
+//
+// Copyright (c) 2025 Röck+Cöde VoF. and the Hummingbird DocC Middleware project authors
+// Licensed under the EUPL 1.2 or later.
+//
+// See LICENSE for license information
+// See CONTRIBUTORS for the list of Hummingbird DocC Middleware project authors
+//
+// ===----------------------------------------------------------------------===
+
+import Hummingbird
+
+import class NIOPosix.NIOThreadPool
+import struct Logging.Logger
+
+/// A middleware that proxies requests to `DocC` documentation containers within a hosting app.
+public struct DocCMiddleware {
+    
+    // MARK: Properties
+    
+    /// A protocol that defines file system interactions.
+    let fileProvider: any FileProvider
+    
+    /// A type that interacts with the logging system.
+    let logger: Logger
+    
+    // MARK: Initializers
+    
+    /// Initializes this middleware with the root path to the `DocC` documentation containers in the file system.
+    /// - Parameters:
+    ///   - pathToRoot: A path to the root folder in which the `DocC` documentation container are located.
+    ///   - logger: A type that interacts with the logging system.
+    ///   - threadPool: A representation of the thread pool that should be used in case some blocking work needs to be performed for which no non-blocking API exists.
+    init(
+        pathToRoot rootFolder: String,
+        logger: Logger,
+        threadPool: NIOThreadPool = .singleton
+    ) {
+        self.fileProvider = LocalFileSystem(
+            rootFolder: rootFolder,
+            threadPool: threadPool,
+            logger: logger
+        )
+        self.logger = logger
+    }
+    
+    /// Initializes this middleware with a type conforming to the `FileProvider` protocol.
+    /// - Parameters:
+    ///   - fileProvider: A type that conforms to the protocol that defines file system interactions.
+    ///   - logger: A type that interacts with the logging system.
+    init(
+        fileProvider: any FileProvider,
+        logger: Logger
+    ) {
+        self.fileProvider = fileProvider
+        self.logger = logger
+    }
+    
+}