feat(cmd): improve error message

The error message displayed in case of a missing Core Lightning configuration file has been enhanced to provide users with more friendly and actionable information.

Now, when coffee fails to find the configuration file at the specified path, it advises users to resolve the issue by running the coffee setup <cln_path> command, helping them quickly address the problem and proceed smoothly.

Signed-off-by: Tarek <tareknaser360@gmail.com>

coffee_core/src/coffee.rs

@@ -201,8 +201,17 @@ impl CoffeeManager {
         let path = self.config.cln_config_path.clone().unwrap();
         let mut file = CLNConf::new(path.clone(), true);
         log::info!("looking for the cln config: {path}");
-        file.parse()
-            .map_err(|err| CoffeeError::new(err.core, &err.cause))?;
+        file.parse().map_err(|err| {
+            CoffeeError::new(
+                err.core,
+                format!(
+                    "coffee was unable to locate Core Lightning configuration file at the specified path: {}.
+                     To resolve this, please run the following command: coffee setup <cln_path>.",
+                    path
+                )
+                .as_str(),
+            )
+        })?;
         log::trace!("{:?}", file.fields);
         self.cln_config = Some(file);
         Ok(())