Modernized the shaders

[Ghost---Shadow]

The shaders were not compatible with my graphics card and were creating
weird artifacts i.e. rendering the UV instead of the mesh.

I made some minor changes and the problem was solved.

[BennyQBD]

(This comment was copied from the previous discussion, in case you aren't looking at that any more)

The attributes aren't getting bound properly. This is an oversight on my part; for some reason I left the attribute binding calls out of this version of the repository, even though I mentioned them in the series.

Oddly enough, I'd even fixed this a while ago, but I completely forgot to commit the changes to github. I apologize for the inconvenience that my oversights have caused you.

In any case, I suggest trying the current version of the repository. It should work just fine.