update readme

Author: jensendarren

README.md

@@ -6,10 +6,10 @@ This tutorial was insprired from the [Encapsulation SOLID](https://app.pluralsig
 
 SOLID is an acronym for the following:
 
-* S - Single Responsibility Principle ([SRP](./srp))
-* O - Open Closed Principle (OCP)
-* L - Liskov Substitution Principle (LSP)
-* I - Interface Segregation Principle (ISP)
-* D - Dependency Inversion Principle (DIP)
+* **S** - Single Responsibility Principle ([SRP](./srp))
+* **O** - Open Closed Principle (OCP)
+* **L** - Liskov Substitution Principle (LSP)
+* **I** - Interface Segregation Principle (ISP)
+* **D** - Dependency Inversion Principle (DIP)
 
 Navigate to the separate folder linked above in this repo for further explainations and an example application written in [Typescript](https://www.typescriptlang.org/).