Update README.md

Author: amirhnajafiz

README.md

@@ -1,9 +1,13 @@
-<h1 align="center"> 
-Test Containers
+<h1 align="center">
+	Test Containers
 </h1>
 
 Example of using Test containers in Golang. Creating a **redis** cluster with
-containers and test redis cluster with Golang SDK.
+containers and test redis cluster with Golang SDK while running unit tests.
+
+We use _test-containers_ to run our dependent services like databases in a container
+hense we won't need to mock them or use real external services. This makes our uint tests more
+efficient and more reliable. Let's see an example.
 
 ## Redis container