Add content for junit (#2371)

* Updated and Added the content to 100-junit.md file

[#1840](https://github.com/kamranahmedse/developer-roadmap/issues/1840) I added the content to 100-junit.md file of the 106-qa-reporting folder to resolve this issue. Please check into this PR!

* Update content/roadmaps/113-qa/content/106-qa-reporting/100-junit.md

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

content/roadmaps/113-qa/content/106-qa-reporting/100-junit.md

@@ -1 +1,6 @@
-# Junit
+# JUnit
+
+JUnit is known as a unit testing framework used for the Java programming language. JUnit has been playing a crucial in the development of test-driven development and is one of a family of unit testing frameworks. JUnit is useful to write repeatable tests for your application code units. JUnit stimulates the idea of “testing first, then coding,”. The test approach explicates –test a little + code a little = JUnit. JUnit helps the programmer by increasing the productivity and the stability of the program’s code snippets.That will helps in reducing the time of the tester, which is spent on debugging of the code.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.tutorialspoint.com/junit/junit_test_framework.htm'>What is JUnit?</BadgeLink>