docs: case put sml telnet

docs/examples/rust/nativeexample/examples/schemaless_insert_telnet.rs

+use taos_query::common::SchemalessPrecision;
+use taos_query::common::SchemalessProtocol;
+use taos_query::common::SmlDataBuilder;
+
+use crate::AsyncQueryable;
+use crate::AsyncTBuilder;
+use crate::TaosBuilder;
+
+async fn put_telnet() -> anyhow::Result<()> {
+    // std::env::set_var("RUST_LOG", "taos=trace");
+    std::env::set_var("RUST_LOG", "taos=debug");
+    pretty_env_logger::init();
+    let dsn =
+        std::env::var("TDENGINE_ClOUD_DSN").unwrap_or("http://localhost:6041".to_string());
+    log::debug!("dsn: {:?}", &dsn);
+
+    let client = TaosBuilder::from_dsn(dsn)?.build().await?;
+
+    let db = "test_schemaless_ws";
+
+    client.exec(format!("drop database if exists {db}")).await?;
+
+    client
+        .exec(format!("create database if not exists {db}"))
+        .await?;
+
+
+    let data = [
+        "meters.current 1648432611249 10.3 location=California.SanFrancisco group=2",
+        "meters.current 1648432611250 12.6 location=California.SanFrancisco group=2",
+        "meters.current 1648432611249 10.8 location=California.LosAngeles group=3",
+        "meters.current 1648432611250 11.3 location=California.LosAngeles group=3",
+        "meters.voltage 1648432611249 219 location=California.SanFrancisco group=2",
+        "meters.voltage 1648432611250 218 location=California.SanFrancisco group=2",
+        "meters.voltage 1648432611249 221 location=California.LosAngeles group=3",
+        "meters.voltage 1648432611250 217 location=California.LosAngeles group=3",
+    ]
+    .map(String::from)
+    .to_vec();
+
+    // demo with all fields
+    let sml_data = SmlDataBuilder::default()
+        .db(db.to_string())
+        .protocol(SchemalessProtocol::Telnet)
+        .precision(SchemalessPrecision::Millisecond)
+        .data(data.clone())
+        .ttl(1000)
+        .req_id(200u64)
+        .build()?;
+    assert_eq!(client.put(&sml_data).await?, ());
+
+    // demo with default precision
+    let sml_data = SmlDataBuilder::default()
+        .db(db.to_string())
+        .protocol(SchemalessProtocol::Telnet)
+        .data(data.clone())
+        .ttl(1000)
+        .req_id(201u64)
+        .build()?;
+    assert_eq!(client.put(&sml_data).await?, ());
+
+    // demo with default ttl
+    let sml_data = SmlDataBuilder::default()
+        .db(db.to_string())
+        .protocol(SchemalessProtocol::Telnet)
+        .data(data.clone())
+        .req_id(202u64)
+        .build()?;
+    assert_eq!(client.put(&sml_data).await?, ());
+
+    // demo with default req_id
+    let sml_data = SmlDataBuilder::default()
+        .db(db.to_string())
+        .protocol(SchemalessProtocol::Telnet)
+        .data(data.clone())
+        .build()?;
+    assert_eq!(client.put(&sml_data).await?, ());
+
+    client.exec(format!("drop database if exists {db}")).await?;
+
+    Ok(())
+}
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