fix(examples): add servers in examples's readme (#229)

Signed-off-by: jokemanfire <hu.dingyang@zte.com.cn>

examples/servers/src/counter_stdio.rs

@@ -0,0 +1,25 @@
+use anyhow::Result;
+use common::counter::Counter;
+use rmcp::{ServiceExt, transport::stdio};
+use tracing_subscriber::{self, EnvFilter};
+mod common;
+/// npx @modelcontextprotocol/inspector cargo run -p mcp-server-examples --example std_io
+#[tokio::main]
+async fn main() -> Result<()> {
+    // Initialize the tracing subscriber with file and stdout logging
+    tracing_subscriber::fmt()
+        .with_env_filter(EnvFilter::from_default_env().add_directive(tracing::Level::DEBUG.into()))
+        .with_writer(std::io::stderr)
+        .with_ansi(false)
+        .init();
+
+    tracing::info!("Starting MCP server");
+
+    // Create an instance of our counter router
+    let service = Counter::new().serve(stdio()).await.inspect_err(|e| {
+        tracing::error!("serving error: {:?}", e);
+    })?;
+
+    service.waiting().await?;
+    Ok(())
+}