Implemented (a first version of) the DocCMiddleware middleware in the library target.

Library/Sources/Internal/Protocols/Pathable.swift

@@ -0,0 +1,16 @@
+protocol Pathable {
+    
+    // MARK: Properties
+    
+    var path: String { get }
+    
+}
+
+// MARK: - String+Formats
+
+extension String {
+    enum Format {
+        static let pathDocs = "/docs/%@"
+        static let pathRoot = "/%@"
+    }
+}