Added factorial in java and python in math folder

Author: AtieveWadhwa

contributors.md

@@ -37,4 +37,5 @@
 35. [Shrey Aryan](https://github.com/shrey183)
 36 [Kautuk Kundan](https://github.com/kautukkundan)
 37. [Deepanshu Jain](https://github.com/thedeepanshujain)
-38. [Your Name](https://github.com/yourusername)
+38. [Atieve Wadhwa](https://github.com/AtieveWadhwa)
+39. [Your Name](https://github.com/yourusername)