feat: Add watering (#27)

src/features/grid/components.rs

@@ -10,6 +10,9 @@ pub struct Tile {
 #[derive(Component)]
 pub struct CropVisual;
 
+#[derive(Component)]
+pub struct WaterVisual;
+
 #[derive(Component, Default, Serialize, Deserialize, Clone, Debug)]
 pub enum TileState {
     #[default]
@@ -17,6 +20,7 @@ pub enum TileState {
     Empty,
     Occupied {
         seed: ItemType,
+        watered: bool,
     },
 }