🚀 Feature Proposal

Adding leading zero in the question number will be an awesome feature for file explorer to sort files by the name.

Python 3.9 will be released on October 5th. Among the chances for this version, dict now supports | and |=, respectively for merge and update. See https://www.python.org/dev/peps/pep-0584/

Since IntervalDict aims to follow the interface of a traditional dict, we should implement them as well.
|= will be easy to do, since we can simply delegate to IntervalDict.update.
For |,

Currently the instance is derive. But it's possible to implement more efficient instance

Go the following link to see the problem statement and add solution into the appropriate folder.
https://www.hackerrank.com/challenges/chocolate-feast/problem