Update README.md

Author: MitkoVtori

README.md

@@ -19,7 +19,7 @@ Course Exercise Lecturer - **[Diyan Kalaydzhiev](https://github.com/DiyanKalaydz
 | <a href="Advanced/4.Error Handling">Error Handling</a> | <a href="OOP/4.Encapsulation">Encapsulation</a> |
 | <a href="Advanced/5.File Handling">File Handling</a>  | <a href="OOP/5.Static and Class Methods">Static and Class Methods</a> |
 | <a href="Advanced/6.Workshop">Workshop</a> | <a href="OOP/6.Polymorphism and Abstraction">Polymorphism and Abstraction</a> |
-| <a href="Advanced/7.Modules">Modules</a> | SOLID |
+| <a href="Advanced/7.Modules">Modules</a> | <a href="OOP/7.SOLID">SOLID</a> |
 | <a href="Advanced/Exam Preparation">Exam Preparation</a> | Iterators and Generators |
 | <a href="Advanced/Regular Exam">Regular Exam</a> | Decorators |
 |  | Testing |