doc: Fix titles.

Author: freezy

VisualPinball.Unity/Documentation~/creators-guide/tutorials/realistic-backglass/1-prepare-artwork.md

@@ -8,13 +8,13 @@ description: How to edit art in Photoshop
 
 Perhaps the most challenging aspect to making a working backglass is finding good artwork. The best possible art is a direct scan of the backglass but that is not always possible. There are backglass images that can be found online but it takes a fair amount of time to clean these up and remove any artifact from them. Another possibility is to get artwork online and use that as a basis for a total redraw.
 
-# Create the Color Map
+## Create the Color Map
 
 Once you have your artwork secured save this as a PNG file. We'll name it `albedo.png` since it'll become our diffuse, or color map. Make sure that the areas for the score reels and credit reel set as transparent. Also be sure to size the backglass image to the size of the original backglass, in the case of Volley this is 19 ¾" x 22".
 
 ![Color Edit](ps-albedo.png)
 
-# Create the Thickness Mask
+## Create the Thickness Mask
 
 <img src="photo-backside.jpg" width="300" class="img-responsive pull-right" style="margin-left: 15px">