Applied google-readability-namespace-comments clang-tidy fixes

src/class_diagram/generators/plantuml/class_diagram_generator.cc

@@ -537,4 +537,4 @@ void generator::generate(std::ostream &ostr) const
 
     ostr << "@enduml" << '\n';
 }
-}
+} // namespace clanguml::class_diagram::generators::plantuml

src/class_diagram/generators/plantuml/class_diagram_generator.h

@@ -81,7 +81,7 @@ private:
     std::string render_name(std::string name) const;
 };
 
-}
-}
-}
-}
+} // namespace plantuml
+} // namespace generators
+} // namespace class_diagram
+} // namespace clanguml