It's a good practice for every repo. It helps to create a virtual environment locally.

I had trouble running this example on Django 3.1.7
It seems that the issue is with line 1 of booksite/templates/index.html
{% load staticfiles %} has been removed as of Django 3.0
Changing it to {% load static %} resolves the issue
If you would prefer to leave it as is, you may consider updating the readme to mention that the code is not compatible with Django 3.0+

Dear bro following are the issues in your example:

1- Edit button is not working.
2- When we want to add second record and click Add new Book it still shows previously saved record no page refresh.

Please rectify errors.