Restored text missing during wiki sync (thanks @sezero!)

include/SDL3/SDL_rect.h

@@ -90,6 +90,9 @@ typedef struct SDL_Rect
 /**
  * A rectangle stored using floating point values.
  *
+ * The origin of the coordinate space is in the top-left, with increasing values moving down and right.
+ * The properties `x` and `y` represent the coordinates of the top-left corner of the rectangle.
+ *
  * \since This struct is available since SDL 3.2.0.
  *
  * \sa SDL_RectEmptyFloat