Force add the newer files OpenGL-ES 3.0 and Beyond.DevAndTgtEnv.pptx, OpenGL-ES 3.0 and Beyond.MtlsAndLights.pptx, and OpenGL-ES 3.0 and Beyond.Shading.Language.pptx

Signed-off-by: Rudy Cazabon <rudycazabon@gmail.com>