feat: update pi example

Author: bregydoc

examples/pi.rs

@@ -1,12 +1,13 @@
 use auto_rust::auto_implement;
 
 #[auto_implement]
-#[doc = "This function calculates pi with a robust and very fast algorithm."]
+/// This function calculates pi with a robust and very fast algorithm.
 fn calculate_pi_with_n_decimals(n: u32) -> f64 {
     todo!()
 }
 
 fn main() {
     let result = calculate_pi_with_n_decimals(10);
     println!("pi: {}", result);
+    // assert_eq!(result, 3.0418396189294032);
 }