Update Fibonacci example

shared/notes-and-examples/2026.04.08/function_stack.py

@@ -9,4 +9,12 @@
 
 
 def fibonacci(n: int):
-    pass
+    if n < 2:
+        return n
+    else:
+        return fibonacci(n - 1) + fibonacci(n - 2)
+
+print(fibonacci(5))
+print(fibonacci(6))
+print(fibonacci(7))
+print(fibonacci(8))