Implemented the DocCMiddleware.Configuration type in the library target.

Sources/DocCMiddleware/Public/Configurations/DoccMiddlewareConfiguration.swift

@@ -1,8 +1,52 @@
+// ===----------------------------------------------------------------------===
 //
-//  File.swift
-//  hummingbird-docc-middleware
+// This source file is part of the Hummingbird DocC Middleware open source project
 //
-//  Created by Javier Cicchelli on 23/09/2025.
+// 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 Foundation
+import class NIOPosix.NIOThreadPool
+
+extension DocCMiddleware {
+    /// A type that contains all the parameters to configure the ``DocCMiddleware`` middleware.
+    public struct Configuration: Sendable {
+        
+        // MARK: Properties
+        
+        /// A path to the physical location where the `DocC` documentation containers are stored.
+        let folderRoot: String
+        
+        /// A URI path that prefixes the `DocC` documentation resources.
+        let uriRoot: String
+        
+        /// A type that define a mechanism to use in case some blocking work needs to be performed for which no non-blocking API exists.
+        let threadPool: NIOThreadPool
+        
+        // MARK: Initializers
+        
+        /// Initializes this configuration type.
+        ///
+        /// > important: It is assumed that both the `uriRoot` and the `folderRoot` parameters should not be empty, and that they should be prefixed
+        /// with the `/` forward slash character.
+        ///
+        /// - Parameters:
+        ///   - uriRoot: A URI path that prefixes the `DocC` documentation resources.
+        ///   - folderRoot: A path to the physical location where the `DocC` documentation containers are stored.
+        ///   - threadPool: A type that define a mechanism to use in case some blocking work needs to be performed for which no non-blocking API exists.
+        public init(
+            uriRoot: String,
+            folderRoot: String,
+            threadPool: NIOThreadPool = .singleton
+        ) {
+            self.folderRoot = folderRoot
+            self.uriRoot = uriRoot
+            self.threadPool = threadPool
+        }
+
+    }
+}