doc(examples): replace clone + assignment with clone_from

Addresses `clippy::assigning_clones` lint.

examples/todomvc/src/main.rs

@@ -73,7 +73,7 @@ impl Component for App {
                     .filter(|e| self.state.filter.fits(e))
                     .nth(idx)
                     .unwrap();
-                self.state.edit_value = entry.description.clone();
+                self.state.edit_value.clone_from(&entry.description);
                 self.state.clear_all_edit();
                 self.state.toggle_edit(idx);
             }