Update src/print.rs

Co-authored-by: Amanieu d'Antras <amanieu@gmail.com>

src/print.rs

@@ -87,10 +87,11 @@ impl<'a, 'b> BacktraceFmt<'a, 'b> {
         Ok(())
     }
 
-    /// Write a string to the backtrace output.
+    /// Inserts a message in the backtrace output.
     ///
-    /// This is only for those messages which is not part of any frame,
-    /// and this won't increment the `frame_index` like frame
+    /// This allows information to be inserted between frames, 
+    /// and won't increment the `frame_index` unlike the `frame`
+    /// method.
     pub fn message(&mut self, msg: &str) -> fmt::Result {
         self.fmt.write_str(msg)
     }