Make Result and ReedlineError public (#661)

* Make `Result` and `ReedlineError` public

Allows implementing custom `History` types

* Fix: style

* Add rustdoc for reedline::Result

src/lib.rs

@@ -239,7 +239,7 @@ mod engine;
 pub use engine::Reedline;
 
 mod result;
-pub(crate) use result::Result;
+pub use result::{ReedlineError, Result};
 
 mod history;
 #[cfg(any(feature = "sqlite", feature = "sqlite-dynlib"))]

src/result.rs

@@ -30,5 +30,5 @@ impl Display for ReedlineError {
 }
 impl std::error::Error for ReedlineError {}
 
-// for now don't expose the above error type to the public
+/// Standard [`std::result::Result`], with [`ReedlineError`] as the error variant
 pub type Result<T> = std::result::Result<T, ReedlineError>;