chore: update documentation

plugins/nfc/src/error.rs

@@ -4,12 +4,21 @@
 
 use serde::{ser::Serializer, Serialize};
 
+/// Alias for a [`std::result::Result`] with the error type [`Error`].
 pub type Result<T> = std::result::Result<T, Error>;
 
+/// Errors returned by the NFC plugin.
+///
+/// Serializes to the error message string, so it can be returned directly from a command.
 #[derive(Debug, thiserror::Error)]
 pub enum Error {
+    /// An I/O error happened.
     #[error(transparent)]
     Io(#[from] std::io::Error),
+    /// The call to the Android or iOS plugin implementation failed,
+    /// either because the arguments could not be serialized, the response could not be
+    /// deserialized or the native side rejected the call (e.g. NFC is unavailable
+    /// or the tag could not be read or written).
     #[cfg(mobile)]
     #[error(transparent)]
     PluginInvoke(#[from] tauri::plugin::mobile::PluginInvokeError),