Move shaders into glsl and hlsl directories

Move `data/shaders` to `data/shaders/glsl`
Move `data/hlsl` to `data/shaders/hlsl`

Fix up shader paths in the cpp files to point to the new glsl location.

`data/shaders/hlsl/compile.py` still overwrites the glsl .spv files (for
now).

Issue: #723

data/shaders/hlsl/descriptorsets/cube.frag

@@ -0,0 +1,16 @@
+// Copyright 2020 Google LLC
+
+Texture2D textureColorMap : register(t1);
+SamplerState samplerColorMap : register(s1);
+
+struct VSOutput
+{
+[[vk::location(0)]] float3 Normal : NORMAL0;
+[[vk::location(1)]] float3 Color : COLOR0;
+[[vk::location(2)]] float2 UV : TEXCOORD0;
+};
+
+float4 main(VSOutput input) : SV_TARGET
+{
+	return textureColorMap.Sample(samplerColorMap, input.UV) * float4(input.Color, 1.0);
+}

data/shaders/hlsl/descriptorsets/cube.vert

@@ -0,0 +1,35 @@
+// Copyright 2020 Google LLC
+
+struct VSInput
+{
+[[vk::location(0)]] float3 Pos : POSITION0;
+[[vk::location(1)]] float3 Normal : NORMAL0;
+[[vk::location(2)]] float2 UV : TEXCOORD0;
+[[vk::location(3)]] float3 Color : COLOR0;
+};
+
+struct UBOMatrices {
+	float4x4 projection;
+	float4x4 view;
+	float4x4 model;
+};
+
+cbuffer uboMatrices : register(b0) { UBOMatrices uboMatrices; };
+
+struct VSOutput
+{
+	float4 Pos : SV_POSITION;
+[[vk::location(0)]] float3 Normal : NORMAL0;
+[[vk::location(1)]] float3 Color : COLOR0;
+[[vk::location(2)]] float2 UV : TEXCOORD0;
+};
+
+VSOutput main(VSInput input)
+{
+	VSOutput output = (VSOutput)0;
+	output.Normal = input.Normal;
+	output.Color = input.Color;
+	output.UV = input.UV;
+	output.Pos = mul(uboMatrices.projection, mul(uboMatrices.view, mul(uboMatrices.model, float4(input.Pos.xyz, 1.0))));
+	return output;
+}