Add content for integration testing (#1926)

* Update integration-testing.md

* Update content/roadmaps/113-qa/content/100-qa-basics/107-testing-techniques/100-functional-testing/integration-testing.md

Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

content/roadmaps/113-qa/content/100-qa-basics/107-testing-techniques/100-functional-testing/integration-testing.md

@@ -1 +1,6 @@
-# Integration testing
+# Integration Testing
+
+Integration Testing is a type of testing where software modules are integrated logically and tested as a group. A typical software project consists of multiple software modules coded by different programmers. This testing level aims to expose defects in the interaction between these software modules when they are integrated. Integration Testing focuses on checking data communication amongst these modules.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.guru99.com/integration-testing.html'>Integration Testing Tutorial</BadgeLink>