added the a scripts help generate secret key

[martcpp]

This pull request involves changes to improve the configuration and security of a Django project. The most significant changes include the introduction of a script to generate a secret key, changes to the ALLOWED_HOSTS and SECRET_KEY settings in hello_world/settings.py, and updates to the README.md and .env.example files.

Security improvements:

• secretgen.py: A new Python script was added to generate a random secret key for Django projects. This script uses Django's get_random_secret_key function to generate the key and instructs the user to replace the secret key in their .env file with the generated key.

Documentation updates:

• README.md: Instructions were added on how to generate a secret key for a Django project using the new secretgen.py script.