clean up docs

Co-authored-by: JoJoJet <21144246+JoJoJet@users.noreply.github.com>

crates/bevy_app/src/app.rs

@@ -94,13 +94,13 @@ struct SubApp {
 }
 
 impl SubApp {
-    /// run the `SubApp`'s schedule
+    /// Runs the `SubApp`'s schedule.
     pub fn run(&mut self) {
         self.app.schedule.run(&mut self.app.world);
         self.app.world.clear_trackers();
     }
 
-    /// extract data from main world to sub app
+    /// Extracts data from main world to this sub-app.
     pub fn extract(&mut self, main_world: &mut World) {
         (self.extract)(main_world, &mut self.app);
     }

crates/bevy_ecs/src/schedule/mod.rs

@@ -361,7 +361,7 @@ impl Schedule {
             .and_then(|stage| stage.downcast_mut::<T>())
     }
 
-    /// Remove a [`Stage`] from the schedule
+    /// Removes a [`Stage`] from the schedule.
     pub fn remove_stage(&mut self, stage_label: impl StageLabel) -> Option<Box<dyn Stage>> {
         let label = stage_label.as_label();
 

crates/bevy_render/src/lib.rs

@@ -92,7 +92,7 @@ pub enum RenderStage {
     Cleanup,
 }
 
-/// Resource for holding the extract stage of the rendering schedule
+/// Resource for holding the extract stage of the rendering schedule.
 #[derive(Resource)]
 pub struct ExtractStage(pub SystemStage);