Add get_key sample

Author: heaths

sdk/security_keyvault/examples/get_key.rs

@@ -0,0 +1,20 @@
+use azure_security_keyvault::{prelude::KeyVaultKey, KeyClient};
+use std::env;
+
+#[tokio::main]
+async fn main() -> azure_core::Result<()> {
+    tracing_subscriber::fmt().init();
+
+    let keyvault_url =
+        env::var("KEYVAULT_URL").expect("Missing KEYVAULT_URL environment variable.");
+    let key_name = env::var("KEYVAULT_KEY").expect("Missing KEYVAULT_KEY environment variable.");
+
+    let credential = azure_identity::create_credential()?;
+
+    let client = KeyClient::new(&keyvault_url, credential)?;
+
+    let key: KeyVaultKey = client.get(key_name).await?;
+    println!("{key:#?}");
+
+    Ok(())
+}