Added the "init(uriRoot:)" initializer function for the CheckURIUseCase use case in the library target and also, improved its test cases.

Sources/HummingbirdDocC/Internal/Use Cases/CheckURIUseCase.swift

@@ -14,6 +14,22 @@ import struct HummingbirdCore.URI
 
 /// A use case that checks whether a given URI against a set of conditions, to determine whether the URI could be used by the middleware or not.
 struct CheckURIUseCase {
+    
+    // MARK: Properties
+    
+    /// A root path that prefixes the documentation resource.
+    private let uriRoot: String
+    
+    // MARK: Initializers
+    
+    /// Initializes this use case.
+    ///
+    /// > important: It is assumed that the `uriRoot` parameter is not empty and that it is prefixed by the `/` character.
+    ///
+    /// - Parameter uriRoot: A root path that prefixes the documentation resource.
+    init(uriRoot: String) {
+        self.uriRoot = uriRoot
+    }
 
     // MARK: Functions
     
@@ -23,8 +39,8 @@ struct CheckURIUseCase {
     func callAsFunction(_ uri: URI) -> String? {
         guard
             let uriPath = uri.path.removingPercentEncoding,
-            !uriPath.contains(.Path.previousFolder),
-            uriPath.hasPrefix(.Path.forwardSlash)
+            uriPath.hasPrefix(uriRoot),
+            !uriPath.contains(.Path.previousFolder)
         else {
             return nil
         }