Add IntelliJ setup instructions

Signed-off-by: Joern Bernhardt <jb@campudus.com>
added sequence and traverse [exercise 4.7]

Signed-off-by: Joern Bernhardt <jb@campudus.com>
additional stream exercises (zipAll, startsWith, tails, scanRight)

Signed-off-by: Joern Bernhardt <jb@campudus.com>
first 5 chapters

Signed-off-by: Joern Bernhardt <jb@campudus.com>