Update hello_material.adoc

Modified Default Material Definitions table columns to 20.40.40 to give more space to column 2 and 3 by moving /Common/MatDefs from cell 1 definition to the description prior to the table.

src/docs/asciidoc/jme3/beginner/hello_material.adoc

@@ -307,21 +307,21 @@ To deactivate Shininess, do not set `Shininess` to 0, but instead set the `Specu
 
 == Default Material Definitions
 
-As you have seen, you can find the following default materials in `jme/core-data/Common/…`.
-[cols="30,35,35", options="header"]
+As you have seen, you can find the following default materials in `jme/core-data/Common/MatDefs/…`.
+[cols="20,40,40", options="header"]
 |===
 
 a| Default Definition 
 a| Usage 
 <a| Parameters  
 
-a| `MatDefs/Misc/Unshaded.j3md` 
+a| `Misc/Unshaded.j3md` 
 a| Colored: Use with mat.setColor() and ColorRGBA. +
 Textured: Use with mat.setTexture() and Texture. 
 a| Color : Color +
 ColorMap : Texture2D 
 
-<a| `MatDefs/Light/Lighting.j3md`      
+<a| `Light/Lighting.j3md`      
 a| Use with shiny Textures, Bump- and NormalMaps textures. +
 Requires a light source. 
 a| Ambient, Diffuse, Specular : Color +