🚀 Feature: Demo function in Python to calculate user rankings based on their activities

[gireeshp]

💭 Description

This is a supporting function to a fitness challenge app built using Appwrite & Flutter. The function should calculate user rankings (leaderboard) based on the user activities.

👀 Have you spent some time to check if this issue has been raised before?

• I checked and didn't find similar issue

🏢 Have you read the Code of Conduct?

• I have read the Code of Conduct