Added more resources in java roadmap (#2836)

* Replaced paid resource with free one

* Added new resources

content/roadmaps/110-java/content/100-java-fundamentals/104-datastructures.md

@@ -10,5 +10,5 @@ As the name indicates itself, a **Data Structure** is a way of organizing the da
 <ResourceGroupTitle>Free Content</ResourceGroupTitle>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.geeksforgeeks.org/data-structures'>What are Data Structures?</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.javatpoint.com/data-structure-tutorial'> Data Structures and Algorithms</BadgeLink>
-<BadgeLink badgeText='Watch' href='https://www.coursera.org/learn/data-structures'>Data Structures and Algorithms</BadgeLink>
+<BadgeLink badgeText='Watch' href='https://youtube.com/playlist?list=PL9gnSGHSqcnr_DxHsP7AW9ftq0AtAyYqJ'>Java + DSA + Interview Preparation Course</BadgeLink>
 <BadgeLink badgeText='Watch' href='https://www.youtube.com/watch?v=9rhT3P1MDHk&list=PLkZYeFmDuaN2-KUIv-mvbjfKszIGJ4FaY'>Data Structures Illustrated</BadgeLink>

content/roadmaps/110-java/content/100-java-fundamentals/readme.md

@@ -8,6 +8,7 @@ Learn about the fundamentals of Java such as basic syntax, data types, variables
 
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.w3schools.com/java/'>Java Basics - W3Schools</BadgeLink>
 <BadgeLink colorScheme='purple' badgeText='Watch' href='https://youtu.be/eIrMbAQSU34'>Java Tutorial for Beginners</BadgeLink>
+<BadgeLink badgeText='Watch' href='https://youtube.com/playlist?list=PL9gnSGHSqcnr_DxHsP7AW9ftq0AtAyYqJ'>Java + DSA + Interview Preparation Course (For beginners)</BadgeLink>
 <ResourceGroupTitle>Books</ResourceGroupTitle>
 
 <BadgeLink colorScheme='purple' badgeText='Book' href='https://www.amazon.co.uk/Head-First-Java-3rd-Brain-Friendly/dp/1491910771'>Head First Java</BadgeLink>