Devcontainer and dev_server.py for local dev

[chrism-pricedev]

Hope this helps:

• Devcontainer configuration for vscode builds this project in Docker.
• Created dev_server.py to run the server from http, https using standard or custom ports.
• requirements.txt added to support Python project dependencies.
• Documented README.md with devcontainer info and runtime commands.
• Tested building & running the project locally on various ports and http/https protocol.