Add some JUnit resources (#1543)

* Add some JUnit resources

* Update content/roadmaps/110-java/content/107-testing-java-apps/104-junit.md

Co-authored-by: sk8higher <sk8higher@iballwasrawt.ru>
Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

content/roadmaps/110-java/content/107-testing-java-apps/104-junit.md

@@ -1 +1,9 @@
-# Junit
+# JUnit
+
+JUnit is a testing framework for Java.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='blue' badgeText='Official Site' href='https://junit.org/junit5/docs/current/user-guide/'>Official Documentation</BadgeLink>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.guru99.com/junit-tutorial.html'>JUnit tutorial</BadgeLink>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.baeldung.com/junit-5'>Basic JUnit tutorial</BadgeLink>
+<BadgeLink badgeText='Watch' href='https://www.youtube.com/watch?v=flpmSXVTqBI'>Testing with JUnit crash course</BadgeLink>