fixed typo

[Overv]

Nah, that word should definitely be vector.

[QBouts]

I started typing an explanation as to why it should be vertex, but then I realized my mistake. I was thinking that the Vertex datastructure can be mapped to shader vectors because the memory layout of the glm vecs is the same. But that's not what you were trying to say with that sentence. You were actually pointing out the similarity between glm::vec and the shader vecx types. My bad!