New Custom Blinn Phong shader to debug PBR shader

Started to make a new custom Blinn Phong shader to try and figure out
why my PBR shader isn't working by following the Custom Blinn Phong
shader tutorial from Joachim Holmer (creator of ShaderForge plugin for
Unity) and then going from there!

Can't get the specular to work as I'm not following Unity's own built-in
Blinn Phong but more tests to follow