Rework the tutorial

[jlouvel]

Provide a new tutorial based on a end use case for an AI agent needing a custom MCP server to compose a context tailored to its use case, reusing existing HTTP APIs

[jlouvel]

• Consider evolving from "Hello world" step 1 to "MCP mock" step 2 to Proxy to Consumes externalization
• Consider creating a Pet Store like example involving our mascot Navi and a navy world

[eskenazit]

Draft to validate . Only consider Hub and MCP part for now (Rest is in between).