docs: add required Supabase initialization steps to Docker setup guide

[tamannaa-rath]

Pull Request Description

This PR updates the Docker Compose setup documentation to include the required Supabase database initialization steps.

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Why

Previously, contributors were instructed to configure the environment file and start the application using Docker, but the setup guide did not mention the required database schema creation and product data import process. As a result, contributors could successfully start the frontend and backend containers while product-related functionality remained unavailable due to missing database tables and data.

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Related Issue

Closes #1580

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What Changed

• Added Supabase database initialization steps to the Docker Compose setup guide.
• Documented the required migration scripts for creating application tables.
• Added instructions for importing product data using scripts/import_to_supabase.py.
• Included a note explaining that product-related functionality will not work until the schema and data are initialized.

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How to Test

1. Follow the updated setup instructions.
2. Configure the .env file with valid Supabase credentials.
3. Run the migration scripts in the Supabase SQL Editor:
   • 001_create_benchmark_runs.sql
   • 002_create_products_table.sql
   • 003_create_feedback_submissions.sql
4. Import product data:

python scripts/import_to_supabase.py

5. Start the application:

docker-compose up --build

6. Verify that:
   • The application starts successfully.
   • Product data is available.
   • Product-related endpoints function correctly.

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Labels added: gssoc:approved | mentor:leonagoel | status:review-needed

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