docs: restructure into topical sections and add the four most-asked-for pages (#3044)

docs_src/deploy/tutorial001.py

@@ -0,0 +1,17 @@
+from mcp.server import MCPServer
+from mcp.server.transport_security import TransportSecuritySettings
+
+mcp = MCPServer("Notes")
+
+
+@mcp.tool()
+def add_note(text: str) -> str:
+    """Save a note."""
+    return f"Saved: {text}"
+
+
+security = TransportSecuritySettings(
+    allowed_hosts=["mcp.example.com", "mcp.example.com:*"],
+    allowed_origins=["https://app.example.com"],
+)
+app = mcp.streamable_http_app(transport_security=security)