feat: Add RecursionIsAwsome class with controlled recursive greeting

WHAT the code does:
- Defines a `RecursionIsAwsome` class.
- `sayHi(int n)` method:
  - **Base case**: if `n == 0`, prints `"Done!"` and stops recursion.
  - **Recursive case**: prints `"Hi"`, decrements `n`, and calls itself again.
- `main()` calls `sayHi(5)` to demonstrate.

WHY this matters:
- Shows proper use of **recursion with a base case**.
- Prevents infinite recursion by stopping when `n == 0`.
- Demonstrates decrementing arguments across recursive calls.

HOW it works:
1. `sayHi(5)` → prints `"Hi"` → calls `sayHi(4)`.
2. Continues printing `"Hi"` until `n == 0`.
3. At `n == 0`, prints `"Done!"` and terminates.

Tips & gotchas:
- Works only for non-negative values of `n`.
  Negative values won’t trigger the base case properly.
- Recursion depth depends on `n`; large `n` may cause `StackOverflowError`.
- Could also be written iteratively with a loop, but recursion is great for learning.

Use-cases:
- Educational demo of **recursion with termination condition**.
- Teaching difference between infinite recursion and controlled recursion.
- Can be adapted to countdowns, repeated tasks, or recursive algorithms.

Short key: algo-recursion-sayhi-basecase.

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan

Section10Methods/RecurssionPractice/src/RecursionIsAwsome.java

@@ -1,11 +1,9 @@
 public class RecursionIsAwsome {
-    public static void main(String[] args)
-    {
+    public static void main(String[] args) {
         sayHi(5);
     }
     public static void sayHi(int n) {
-        //Need a Base Case.
-        //Base case means when to stop. printing infinite times.
+        //Need a Base Case. Base case means when to stop. printing infinite times.
         if(n==0) {
             System.out.println("Done!");
         }