chore: update documentation

plugins/barcode-scanner/src/error.rs

@@ -4,12 +4,17 @@
 
 use serde::{ser::Serializer, Serialize};
 
+/// Alias for the result type returned by this crate's functions.
 pub type Result<T> = std::result::Result<T, Error>;
 
+/// The error type returned by this crate's APIs. Serialized as its [`Display`](std::fmt::Display)
+/// string when it crosses the IPC boundary.
 #[derive(Debug, thiserror::Error)]
 pub enum Error {
+    /// An I/O error occurred.
     #[error(transparent)]
     Io(#[from] std::io::Error),
+    /// Failed to run a command on the mobile plugin implementation (Kotlin on Android, Swift on iOS).
     #[cfg(mobile)]
     #[error(transparent)]
     PluginInvoke(#[from] tauri::plugin::mobile::PluginInvokeError),