Added namespaces to some of the constants for the String+Constants extension in the library target.

Sources/DocCMiddleware/Internal/Extensions/String+Constants.swift

@@ -13,8 +13,18 @@
 extension String {
     /// An empty string.
     static let empty = ""
-    /// A forwarding slash.
-    static let forwardSlash = "/"
-    /// An indication of a previous folder in a path component.
-    static let previousFolder = ".."
+    
+    /// A namespace that defines logging representations.
+    enum Logging {
+        /// A name of the middleware that triggered a logging event.
+        static let source = "DocCMiddleware"
+    }
+    
+    /// A namespace that defines relative path representations.
+    enum Path {
+        /// A forwarding slash.
+        static let forwardSlash = "/"
+        /// An indication of a previous folder in a path component.
+        static let previousFolder = ".."
+    }
 }