Add Getting Started for Parallax2D

Author: markdibarry

tutorials/2d/2d_parallax.rst

@@ -16,17 +16,25 @@ up though, so this page provides in-depth descriptions of some properties and ho
     recommended to use over the :ref:`ParallaxLayer<class_parallaxlayer>` and
     :ref:`ParallaxBackground<class_parallaxbackground>` nodes.
 
-Scroll scale
-------------
+Getting started
+---------------
+
+The parallax node supports adding nodes that render things as children, so you can use one or many nodes to make up each
+layer. To begin, place each node or nodes you want to have scroll independently as a child of their own parallax node.
+Make sure that the top left of the textures used are at the ``(0, 0)`` crossing, like in the image below. See the section
+on :ref:`positioning <doc_2d_parallax_positioning>` for why this is important.
+
+.. image:: img/2d_parallax_size_viewport.webp
+
+The scene above uses one prepared texture for the higher clouds in a :ref:`Sprite2D <class_sprite2d>`, but you could
+just as easily use multiple nodes spaced out to compose the layer.
 
 The backbone of the parallax effect is the :ref:`scroll_scale <class_parallax2d_property_scroll_scale>` property.
 It works as a scroll-speed multiplier, allowing layers to move at a different speed than the camera for each axis set.
 A value of 1 makes the parallax node scroll at the same speed as the camera. If you want your image to look further away
 when scrolling, use a value lower than 1, with 0 bringing it to a complete stop. If you want something to appear closer
 to the camera, use a value higher than 1, making it scroll faster.
 
-.. image:: img/2d_parallax_size_viewport.webp
-
 The scene above is comprised of five layers. Some good :ref:`scroll_scale <class_parallax2d_property_scroll_scale>`
 values might be:
 
@@ -119,6 +127,8 @@ Below, you can see that repeating the image twice makes it large enough to cover
 
 .. image:: img/2d_parallax_size_repeat.webp
 
+.. _doc_2d_parallax_positioning:
+
 Poor positioning
 ~~~~~~~~~~~~~~~~