Update README.md

Author: 0xsam1r

README.md

@@ -61,7 +61,7 @@ OOP-Sheets
 │   ├── problem3.cpp   
 │   └── sheet #6.pdf
 ├── sheet7                                         
-│   ├── problem1.cpp       # Multilevel Inheritance
+│   ├── problem1.cpp       # Multilevel Inheritance, override functions
 │   ├── problem2.cpp       # Diamond-shaped inheritance (Hybrid Inheritance)
 │   └── sheet #7.pdf
 ├── sheet8