This takes a set of glsl shader files (extensions: .vs, .vs.glsl, .fs, .fs.glsl)
and converts it to the follow json (based on gltf 1.0):

{   
    [id: string]: Shader; // id = Shader.name + (".vs" | ".fs")  
}  

where Shader =

{  
    name: string;  
    type: 35632 | 35633; // fs = 35632, vs = 35633  
    attributes: string[];  
    uniforms: string[];  
    source: string;  
}