Add docs to bevy_sprite a little (#10947)

# Objective

- bevy_sprite crate is missing docs for important types. `Sprite` being
undocumented was especially confusing for me even though it is one of
the first types I need to learn.
 
## Solution

- Improves the situation a little by adding some documentations.
I'm unsure about my understanding of functionality and writing. I'm
happy to be pointed out any mistakes.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Federico Rinaldi <gisquerin@gmail.com>

crates/bevy_sprite/src/bundle.rs

@@ -10,11 +10,16 @@ use bevy_render::{
 };
 use bevy_transform::components::{GlobalTransform, Transform};
 
+/// A [`Bundle`] of components for drawing a single sprite from an image.
 #[derive(Bundle, Clone, Default)]
 pub struct SpriteBundle {
+    /// Specifies the rendering properties of the sprite, such as color tint and flip.
     pub sprite: Sprite,
+    /// The local transform of the sprite, relative to its parent.
     pub transform: Transform,
+    /// The absolute transform of the sprite. This should generally not be written to directly.
     pub global_transform: GlobalTransform,
+    /// A reference-counted handle to the image asset to be drawn.
     pub texture: Handle<Image>,
     /// User indication of whether an entity is visible
     pub visibility: Visibility,
@@ -24,8 +29,8 @@ pub struct SpriteBundle {
     pub view_visibility: ViewVisibility,
 }
 
-/// A Bundle of components for drawing a single sprite from a sprite sheet (also referred
+/// A [`Bundle`] of components for drawing a single sprite from a sprite sheet (also referred
-/// to as a `TextureAtlas`)
+/// to as a `TextureAtlas`).
 #[derive(Bundle, Clone, Default)]
 pub struct SpriteSheetBundle {
     /// The specific sprite from the texture atlas to be drawn, defaulting to the sprite at index 0.

crates/bevy_sprite/src/collide_aabb.rs

@@ -2,6 +2,7 @@
 
 use bevy_math::{Vec2, Vec3};
 
+/// The side where a collision occurred, as returned by [`collide`].
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
 pub enum Collision {
     Left,

crates/bevy_sprite/src/lib.rs

@@ -1,3 +1,4 @@
+//! Provides 2D sprite rendering functionality.
 mod bundle;
 mod dynamic_texture_atlas_builder;
 mod mesh2d;
@@ -40,11 +41,13 @@ use bevy_render::{
     ExtractSchedule, Render, RenderApp, RenderSet,
 };
 
+/// Adds support for 2D sprite rendering.
 #[derive(Default)]
 pub struct SpritePlugin;
 
 pub const SPRITE_SHADER_HANDLE: Handle<Shader> = Handle::weak_from_u128(2763343953151597127);
 
+/// System set for sprite rendering.
 #[derive(Debug, Hash, PartialEq, Eq, Clone, SystemSet)]
 pub enum SpriteSystem {
     ExtractSprites,

crates/bevy_sprite/src/render/mod.rs

@@ -756,6 +756,7 @@ pub fn prepare_sprites(
     }
 }
 
+/// [`RenderCommand`] for sprite rendering.
 pub type DrawSprite = (
     SetItemPipeline,
     SetSpriteViewBindGroup<0>,

crates/bevy_sprite/src/sprite.rs

@@ -3,6 +3,9 @@ use bevy_math::{Rect, Vec2};
 use bevy_reflect::{std_traits::ReflectDefault, Reflect};
 use bevy_render::color::Color;
 
+/// Specifies the rendering properties of a sprite.
+///
+/// This is commonly used as a component within [`SpriteBundle`](crate::bundle::SpriteBundle).
 #[derive(Component, Debug, Default, Clone, Reflect)]
 #[reflect(Component, Default)]
 #[repr(C)]

crates/bevy_sprite/src/texture_atlas.rs

@@ -22,6 +22,9 @@ pub struct TextureAtlas {
     pub(crate) texture_handles: Option<HashMap<AssetId<Image>, usize>>,
 }
 
+/// Specifies the rendering properties of a sprite from a sprite sheet.
+///
+/// This is commonly used as a component within [`SpriteSheetBundle`](crate::bundle::SpriteSheetBundle).
 #[derive(Component, Debug, Clone, Reflect)]
 #[reflect(Component)]
 pub struct TextureAtlasSprite {