Add Dockerfile and docker-compose for container support

[netra21mohekar]

This pull request adds Docker support to the ToDoList project.

Changes made:

Added a Dockerfile to containerize the frontend application using Node.js and Alpine.

Created a docker-compose.yml file to simplify local development setup.

Why this is useful:

Allows developers to run the project without installing dependencies manually.

Makes the app easier to run in different environments (e.g., cloud, CI/CD).

Provides a consistent setup for onboarding new contributors.

Usage:
To build and run the app using Docker:

bash
Copy code
docker-compose up --build
Let me know if you'd like me to add instructions to the README.

[netra21mohekar]

The failing Netlify checks are likely unrelated to my changes, as this PR only introduces Docker support without modifying any frontend files.