FIX: only display attrs if they exist

.tsk/archive/tsk-6.tsk

···
 automatically add backlinks
 
+I need to parse on save/edit/create for outgoing internal links. If any exist and their
+corresponding task exists, update the targetted task with a backlink reference

src/attrs.rs

···
         }
     }
 
+    pub(crate) fn is_empty(&self) -> bool {
+        self.updated.is_empty() && self.written.is_empty()
+    }
+
     pub(crate) fn iter(
         &self,
     ) -> Chain<BTreeMapIter<'_, String, String>, BTreeMapIter<'_, String, String>> {

src/main.rs

···
 fn command_show(dir: PathBuf, task_id: TaskId, show_attrs: bool) -> Result<()> {
     let task = Workspace::from_path(dir)?.task(task_id.into())?;
     // YAML front-matter style. YAML is gross, but it's what everyone uses!
-    if show_attrs {
+    if show_attrs && !task.attributes.is_empty() {
         println!("---");
         for (attr, value) in task.attributes.iter() {
             println!("{attr}: \"{value}\"");