Some minor docs improvements (#7614)

crates/egui_kittest/src/lib.rs

@@ -52,6 +52,7 @@ impl Display for ExceededMaxStepsError {
 }
 
 /// The test Harness. This contains everything needed to run the test.
+///
 /// Create a new Harness using [`Harness::new`] or [`Harness::builder`].
 ///
 /// The [Harness] has a optional generic state that can be used to pass data to the app / ui closure.

crates/egui_kittest/src/snapshot.rs

@@ -26,6 +26,7 @@ pub struct SnapshotOptions {
 }
 
 /// Helper struct to define the number of pixels that can differ before the snapshot is considered a failure.
+///
 /// This is useful if you want to set different thresholds for different operating systems.
 ///
 /// The default values are 0 / 0.0