Rebuild the docs around tested examples; shrink README.v2.md to a pitch (#2978)

docs_src/client/tutorial005.py

@@ -0,0 +1,20 @@
+from mcp import Client
+from mcp.server import MCPServer
+
+mcp = MCPServer("Bookshop")
+
+
+@mcp.prompt(title="Recommend a book")
+def recommend(genre: str) -> str:
+    """Ask for a recommendation in a genre."""
+    return f"Recommend one {genre} book from the catalog and say why."
+
+
+async def main() -> None:
+    async with Client(mcp) as client:
+        listed = await client.list_prompts()
+        print(listed.prompts)
+
+        result = await client.get_prompt("recommend", {"genre": "poetry"})
+        for message in result.messages:
+            print(message.role, message.content)