cln-plugin: Add options to the getmanifest call

plugins/examples/cln-plugin-startup.rs

@@ -1,12 +1,19 @@
 //! This is a test plugin used to verify that we can compile and run
 //! plugins using the Rust API against c-lightning.
 
-use cln_plugin::Builder;
+use cln_plugin::{options, Builder};
 use tokio;
 
 #[tokio::main]
 async fn main() -> Result<(), anyhow::Error> {
-    let (plugin, stdin) = Builder::new((), tokio::io::stdin(), tokio::io::stdout()).build();
+    let (plugin, stdin) = Builder::new((), tokio::io::stdin(), tokio::io::stdout())
+        .option(options::ConfigOption::new(
+            "test-option",
+            options::Value::Integer(42),
+            "a test-option with default 42",
+        ))
+        .build();
+
     tokio::spawn(async {
         tokio::time::sleep(tokio::time::Duration::from_millis(1000)).await;
         log::info!("Hello world");