added document layouter

tests/concrete/test_new_page_implementation.py

@@ -22,8 +22,8 @@ class SimpleTestRenderable(Renderable, Queriable):
     
     def __init__(self, text: str, size: tuple = (100, 50)):
         self._text = text
-        self._size = size
-        self._origin = np.array([0, 0])
+        self.size = size
+        self.origin = np.array([0, 0])
         
     def render(self):
         """Render returns None - drawing is done via the page's draw object"""