docs: docs error

[Waterkyuu]

Returning only one client is such an absurd error.
// Create SSE client
client := client.NewSSEMCPClient("http://localhost:8080/mcp/sse")

func NewSSEMCPClient(baseURL string, options ...transport.ClientOption) (*Client, error) {
	sseTransport, err := transport.NewSSE(baseURL, options...)
	if err != nil {
		return nil, fmt.Errorf("failed to create SSE transport: %w", err)
	}
	return NewClient(sseTransport), nil
}

client, err := client.NewSSEMCPClient("http://localhost:8080/mcp/sse")