Add chapter with GLSL to HLSL mapping about vulkan-guide

[spencer-lunarg]

100% agree, this would be a very useful addition!

[SaschaWillems]

Awesome. I'll try to get something up and running based on above links. Learned a lot while porting the GLSL shaders for my samples to HLSL that should prove helpful for this :)

[SaschaWillems]

Here is a first very work-in-progress version of what I have in mind: https://github.com/SaschaWillems/Vulkan-Guide/blob/shader_language_mapping/chapters/high_level_shader_language_comparison.adoc

It's still lacking (probably a lot) stuff and needs restructuring. But I can imagine that it would be useful to esp. those that know GLSL and want to move to HLSL.

[spencer-lunarg]

This is awesome! I agree could probably use some small cleanup and restructuring and more stuff added, but just having this nicely together showing the difference is such an useful addition to the ecosystem

[SaschaWillems]

Fixed via #244