fix(cheat): abort when no cheat sheet found for the command

src/error.rs

@@ -15,6 +15,9 @@ pub enum Error {
     /// Error that might occur when running on unsupported platforms.
     #[error("Unsupported platform.")]
     UnsupportedPlatformError,
+    /// Error that might occur when trying to show the cheat sheet
+    #[error("No cheat sheet found for `{0}`")]
+    CheatSheetNotFoundError(String),
 }
 
 /// Type alias for the standard [`Result`] type.

src/helper/docs/cheat.rs

@@ -25,6 +25,9 @@ pub fn show_cheat_sheet<Output: Write>(
         .call()
         .map_err(|e| Error::from(Box::new(e)))?
         .into_string()?;
+    if cheat_sheet.starts_with("Unknown topic.") {
+        return Err(Error::CheatSheetNotFoundError(cmd.into()));
+    }
     if let Some(pager) = pager {
         let mut process = if cfg!(target_os = "windows") {
             Command::new("cmd")