Add Reverse Array example in Python

[Shrihari25-hub]

This PR adds a beginner-friendly Python script to reverse an array.

✅ Demonstrates three different methods to reverse an array:

1. Using slicing
2. Using the reverse() method
3. Using manual element swapping
   ✅ Includes clear comments for beginners
   ✅ Easy-to-understand and practical example for learning

Kindly add the Hacktoberfest-accepted label if possible. 🎉

Thank you for maintaining this beginner-friendly Python repo!