Route to check if number is Harshad Number or not

[jinicode]

Please describe the feature you want this project to offer
Route to check if number is Harshad Number or not

Describe the solution you'd like
add logic to '/harshad' route to check if number is Harshad Number or not

Describe alternatives you've considered (Optional)
A clear and concise description of any alternative solutions or features you've considered.

Additional context (Optional)
Add any other context or screenshots about the feature request here.

[SardulDhyani]

Hi, @jinicode please assign this to me. I will add a new route.

[jinicode]

I have made pr #57 to for harshad number