feat: add shell error enum

src/error.rs

@@ -0,0 +1,3 @@
+pub enum ShellError {
+    Execute(String),
+}

src/main.rs

@@ -1,3 +1,4 @@
+mod error;
 mod execute;
 mod parse;
 mod prompt;
@@ -23,11 +24,9 @@ fn main() -> Result<()> {
                 }
             }
             Err(ReadlineError::Interrupted) => {
-                println!("CTRL-C");
                 break;
             }
             Err(ReadlineError::Eof) => {
-                println!("CTRL-D");
                 break;
             }
             Err(err) => {