Add Parking Lot Link

Author: Tusamma Sal Sabil

readme.md

@@ -23,7 +23,7 @@
 <p align="center">
  <a href="object-oriented-design-case-studies/design-a-library-management-system.md"><b>Design a Library Management System</b></a>
  <br />
- <a href="object-oriented-design-case-studies/"><b>Design a Parking Lot</b></a>
+ <a href="object-oriented-design-case-studies/design-a-parking-lot.md"><b>Design a Parking Lot</b></a>
  <br />
  <a href="object-oriented-design-case-studies/"><b>Design Amazon - Online Shopping System</b></a>
  <br />