chore: Fix several style lints (#17488)

It's not comprehensive enough to start linting on `style` group, but
hey, it's a start.

Release Notes:

- N/A

crates/story/src/story.rs

@@ -184,6 +184,12 @@ pub struct StorySection {
     children: SmallVec<[AnyElement; 2]>,
 }
 
+impl Default for StorySection {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl StorySection {
     pub fn new() -> Self {
         Self {