update coordinate transform info in rendering doc

docs/rendering.md

@@ -28,7 +28,7 @@ struct RenderState {
 The simulation uses an XY plane while rendering uses XZ plane (Y is up in raylib).
 
 **Transformation:**
-- Simulation (X, Y, Z) → Render (X, -Z, Y)
+- Simulation (X, Y, Z) → Render (X, Z, -Y)
 - 90-degree rotation around X-axis
 
 **Implementation:**
@@ -36,8 +36,8 @@ The simulation uses an XY plane while rendering uses XZ plane (Y is up in raylib
 Vector3 sim_to_render(Vec3 pos, double scale) {
     return (Vector3){
         (float)(pos.x * scale),
-        (float)(-pos.z * scale),
+        (float)(pos.z * scale),
-        (float)(pos.y * scale)
+        (float)(-pos.y * scale)
     };
 }
 ```