Add Getting Started for Parallax2D

Author: markdibarry

tutorials/2d/2d_parallax.rst

@@ -16,17 +16,22 @@ 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 textures as child nodes, so you can use one or many textures to make up each layer.
+To begin, place each image or images you want to have scroll independently as a child of their own parallax node.
+Make sure that the top left of your images are at the ``(0,0)`` crossing, like the image below. See the section on
+:ref:`positioning<positioning>` for why this is important.
+
+.. image:: img/2d_parallax_size_viewport.webp
 
 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:
 
@@ -43,6 +48,7 @@ The video below displays how these values affect scrolling while in-game:
    :autoplay:
    :loop:
    :muted:
+   :align: center
 
 Infinite repeat
 ---------------
@@ -119,6 +125,8 @@ Below, you can see that repeating the image twice makes it large enough to cover
 
 .. image:: img/2d_parallax_size_repeat.webp
 
+.. _positioning:
+
 Poor positioning
 ~~~~~~~~~~~~~~~~