ent show: show tags, if any

This simplifies the code flow and gets rid of two levels of indentation.

src/bin/ent/main.rs

@@ -285,10 +285,20 @@ fn handle_command(
 
         Commands::Show { issue_id } => {
             let issues = entomologist::database::read_issues_database(issues_database_source)?;
-            match issues.get_issue(issue_id) {
-                Some(issue) => {
+            let Some(issue) = issues.get_issue(issue_id) else {
+                return Err(anyhow::anyhow!("issue {} not found", issue_id));
+            };
             println!("issue {}", issue_id);
             println!("author: {}", issue.author);
+            if issue.tags.len() > 0 {
+                print!("tags: ");
+                let mut separator = "";
+                for tag in &issue.tags {
+                    print!("{}{}", separator, tag);
+                    separator = ", ";
+                }
+                println!("");
+            }
             println!("creation_time: {}", issue.creation_time);
             if let Some(done_time) = &issue.done_time {
                 println!("done_time: {}", done_time);
@@ -311,11 +321,6 @@ fn handle_command(
                 println!("{}", comment.description);
             }
         }
-                None => {
-                    return Err(anyhow::anyhow!("issue {} not found", issue_id));
-                }
-            }
-        }
 
         Commands::State {
             issue_id,