Add a Code of Conduct for welcoming and inclusive contribution

[Reprompts]

Description:
Currently, the PyApptest repository does not have a Code of Conduct. A Code of Conduct is important to establish a respectful, inclusive, and harassment-free environment for all contributors and users.

By adding this, we can:

Make new contributors feel welcomed and safe.

Set clear expectations about behavior in issues, pull requests, and discussions.

Comply with open-source community standards (required by GitHub Community Profile).

Tasks:

Create a new file named CODE_OF_CONDUCT.md at the root of the project.

Use the Contributor Covenant Code of Conduct v2.1 as a base.

Fill in:

Project maintainers' email address (for reporting issues).

Link the Code of Conduct in the main README.md.

Why This Matters:
A visible Code of Conduct signals to all users and developers that the project maintains professionalism and values contribution from diverse people.

Optional Bonus:

Mention the existence of the Code of Conduct when new contributors open their first pull request via a PR template.

[RautAtharv07]

Hi! I’d like to work on this issue and add a Contributor Covenant Code of Conduct. Can you please assign this to me?