UX Enhancement: Use project_name variable for dynamic log paths instead of hardcoded 'mysite'

[SatyamGupta-py]

Hello! This pull request is to improve the onboarding experience for new developers by making a small adjustment to the settings.py project template.

Context:

When a new developer follows the installation.txt guide, they are encouraged to customize their project name, database, and other settings. For example, a user setting up a project named 'my-project' will create a database, virtual environment, and log directory all using the 'my-project' name. This is a great, intuitive process.

The first time the user runs a command 'python manage.py initial_migrate', they may encounter a:

FileNotFoundError: [Errno 2] No such file or directory: '/var/log/mysite/debug.log'

This happened to me.

This happens because the log path in the settings.py template is currently hardcoded to use 'mysite', while the user has created a log directory matching their custom project name (e.g., /var/log/my-project/). This can cause a pause in the setup process while the user investigates their settings file to align the paths.

UX Enhancement:

This PR replaces the hardcoded 'mysite' in the log path with the {{ project_name }} template variable.

This change ensures that the generated settings.py file automatically uses the correct, custom project name for the log directory, aligning the template's behavior with the instructions in the documentation.