[US-1] Implement GitHub Authentication Strategy

[H-BAHDON]

Description: Integrate the GitHub authentication strategy using passport-github2 in the Node.js application.

Sub tasks:

• Retrieve or generate GitHub client ID and client secret. Save these credentials securely in the .env file. {I'll include it in .env file}
• Create a new authentication strategy using passport-github2. Configure the strategy with the GitHub client ID, client secret, and a callback URL.
• Implement logic within the GitHub authentication strategy to manage how user accounts are created or retrieved based on GitHub information.
• Establish a robust error handling mechanism within the GitHub authentication strategy to address potential issues during the authentication process.

Read more about here: https://www.passportjs.org/packages/passport-github2/