Add .devcontainer config to support GitHub Codespaces and VS Code Dev Containers

[snehanair-486]

Problem

There is currently no .devcontainer/ configuration in the repository. New contributors need to manually install Docker, Docker Compose, Node, and configure environment variables before they can run anything — a process that is underdocumented and error-prone across different host OS setups. This friction slows down first contributions significantly.

Proposed change

Add a .devcontainer/devcontainer.json (and optionally a companion docker-compose.devcontainer.yml) that bootstraps a fully working dev environment with one click in GitHub Codespaces or VS Code. The config should:
— pre-install Docker-in-Docker, Node, and Python dependencies
— set the CELLO_STORAGE_PATH environment variable automatically
— run make local as a post-create command so the stack is ready on first open
— expose ports 8080 and 8081 for the API engine and dashboard

Why this matters

GitHub Codespaces lets contributors open a browser tab and start coding with zero local setup. For an open-source project looking to grow its contributor base, this is one of the highest-leverage single-file additions possible. It also makes CI reproducibility easier since the dev environment is version-controlled.

[DanielNg0729]

Hi maintainers, I’d like to work on this issue.

I’m new to Hyperledger Cello, but I’m familiar with Python, JavaScript, Docker-based development, and VS Code. I’d like to start by adding a minimal .devcontainer/devcontainer.json that helps new contributors run the project in GitHub Codespaces / VS Code Dev Containers.

My initial plan is:

1. Add a basic devcontainer config with Python, Node, Docker-in-Docker support.
2. Set CELLO_STORAGE_PATH automatically.
3. Expose ports 8080 and 8081.
4. Test whether make local can run successfully in the container.
5. Document any limitations if full startup requires host Docker permissions.

Please let me know if this approach is acceptable before I start.