Added an extensive guide to the README outlining the process for setting up a local environment including a `.env.local` file for storing sensitive information safely. Also included are steps on how to integrate with Stripe and set up the related environment variables.
Deleted the billing-redirect-button, checkout-redirect-button, and embedded-stripe-checkout components. Additionally, removed the shadcn directory, which encompassed billing-related icons. This change streamlines the subscription settings interface and organizes the system's payment management. This update is a stepping stone towards improving the billing system's overall architecture.
