[WORKSHOP][google-sheets-mcp] Initial implementation of the demo

[dym-ok]

🟢 RANDOM_DEMO_FOLDER = "demos/google-sheets-mcp/"
⚪ SCRIPT_VERSION = "1.1.0_23sep25"
🔴 USERNAME = "dmytroyurchenko"

This demo is currently in a "NotStarted" state. This issue is to track the initial implementation.

Tasks:

• Create a basic script to interact with Google Sheets using mcp-google-sheets.
• Create a justfile to provide an easy way to run the script.
• Update the README.md with better instructions.

-- Created by Gemini CLI on behalf of dmytroyurchenko. 🤖 👤