Create a Contributing guide for the project

[Dr-Blank]

This project lacks a guide for new contributors, which can be a barrier to entry for potential contributors. We need to create a guide to help new contributors get started. To address this issue and foster a more welcoming environment for new contributors, we need to create a guide that outlines the key aspects they should be aware of when getting involved in the project.

The guide should cover the following topics, among others (not limited to):

Setting Up Development Environment and Testing Environment:

• Instructions for setting up the local development environment, including tools, dependencies, and any environment-specific considerations.
• Guidance on configuring and launching the testing environment, including unit tests, integration tests, or other relevant testing processes.

Project Code Guidelines:

• Information on coding style and conventions used in the project. As we currently use Flake8, specific details regarding its usage and any other code formatting or linting tools should be included.
• Best practices for writing clean, maintainable, and efficient code specific for this project

Code of Conduct and Community Guidelines:

• Information about the project's code of conduct and any specific community guidelines.
• Encouragement to maintain a respectful and inclusive environment for all contributors.

Additional Context

This issue serves as the initial step toward creating a guide for new contributors. Feel free to provide input and suggestions on what should be included in this guide. Once the guide is in place, it will significantly benefit this project and its community.

[JonnyWong16]

Bottom section of the readme is a start.

https://github.com/pkkid/python-plexapi/blob/master/README.rst#L188

It should be moved to a new contributing doc.