message: chore: Add serial-manager feature
  Was commented out when 0.5 landed.
diff: @@ -6,8 +6,9 @@ pub mod xinput;
  use rusty_xinput::XInputUsageError;
  #[cfg(feature = "btleplug-manager")]
  use ::btleplug::Error as BtleplugError;
  -// #[cfg(feature = "serial-manager")]
  +#[cfg(feature = "serial-manager")]
  pub mod serialport;
  +
  use crate::{core::ButtplugResultFuture, device::ButtplugDeviceImplCreator};
  use async_channel::Sender;
  use thiserror::Error;
  