fix: Remove empty lines from `tsk list -a`

Fixes: #2
Signed-off-by: Awiteb <[e-mail]>

src/main.rs

···
         } else {
             for stack_item in stack.into_iter() {
                 if let Some(parsed) = task::parse(&stack_item.title) {
-                    println!("{}\t{}", stack_item.id, parsed.content);
+                    println!("{}\t{}", stack_item.id, parsed.content.trim());
                 } else {
                     println!("{stack_item}");
                 }