v0.2.1

[v0.2.1] change default server settings (add small and large), enable env variables to config appl, update cursorrules

• Can configurate default small and large models, unify the interface (server name) for the developpers and users.
• Enable using environmental variable to update appl configs (requires jsonargparse).
• Update cursorrules to better use cursor to compose codes.
• Update docs for setup observability platforms.
• Support caching request with response_format as a pydantic model.
• Add .env.example to help setup for new projects.
• Add hint when Langfuse or Lunary is not configured.