Updated test cases documentation

docs/test_cases/t00041.md

@@ -16,6 +16,8 @@ diagrams:
         - clanguml::t00041
       context:
         - clanguml::t00041::RR
+      subclasses:
+        - clanguml::t00041::ns1::N
 ```
 ## Source code
 File t00041.cc
@@ -54,6 +56,17 @@ struct RR : public R {
 struct RRR : public RR {
 };
 
+namespace ns1 {
+struct N {
+};
+
+struct NN : public N {
+};
+
+struct NM : public N {
+};
+}
+
 } // namespace clanguml::t00041
 
 ```