make a start toward better error handling

src/lib.rs

@@ -7,6 +7,7 @@ use loe::{process, Config, TransformMode};
 pub mod colour;
 pub mod dialogue;
 pub mod ending;
+pub mod error;
 pub mod exit;
 pub mod game;
 pub mod image;
@@ -24,6 +25,7 @@ pub mod test_omnibus;
 pub use colour::Colour;
 pub use dialogue::Dialogue;
 pub use ending::Ending;
+pub use error::Error;
 pub use exit::*;
 pub use game::*;
 pub use image::Image;