various updates

Signed-off-by: Michael Lodder <[email protected]>

Author: mikelodder7

ursa_core/src/error.rs

@@ -3,6 +3,7 @@ use thiserror::Error as ThisError;
 
 /// The common errors that can occur in Ursa
 #[derive(ThisError, Debug)]
+#[non_exhaustive]
 pub enum UrsaError {
     /// Convert IO errors
     #[error("io error")]

ursa_core/src/lib.rs

@@ -1,4 +1,5 @@
-//!
+//! This crate contains shared components used among the
+//! Ursa library
 
 #![deny(
     unused_variables,
@@ -22,4 +23,3 @@ pub use serde_json;
 
 /// The errors generated by ursa components
 pub use error::*;
-