Add handlebars templates for prompts

[elfedy]

• Use handlebars to write templates.
• Replace prompt "handler" logic as now rendering the prompt is the same for all.
• Move all Prompts to a dedicated file
• Simplify some of the analysis prompts
• Add tests to ensure prompts render correctly using the handle_get_prompt entrypoint.
• Organize README a little bit better.

[snowmead]

I keep the fork of modelcontextprotocol/rust-sdk up to date. If you want to avoid doing all the manual work of implementing the prompt protocol - you can import from:

git = "https://github.com/snowmead/rust-sdk", branch = "feature/prompt-support"

Once merged, you can switch back to upstream

[notlesh]

Should we remove this fn from the ServerHandler trait?

[elfedy]

The trait comes from rmcp crate and is used to then implement the mcp protocol. Also, we might want to use the context at some point, for example to implement logging.

[notlesh]

Oh, duh, I was thinking ServerHandler came from our crate. 🥵

[notlesh]

LGTM, I left a couple minor comments.