12.7. Conditional Operator: Introduce chaining ternay operators

[karimdevelops]

Introduced the concept of chaining ternary operators, it is a fun little concept for beginners.

Along with explanation, I included these snippets:

String message = age <= 0
    ? "You do not exist yet"
    : age > 100
    ? "Sorry, you are too old."
    : age < 25
    ? "You cannot rent a car!"
    : "You might be able to rent a car";

CONDITION ? WHEN_TRUE : CONDITION ? WHEN_TRUE : CONDITION ? WHEN_TRUE ... : WHEN_ALL_FALSE