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/displacement/displacement.tese

@@ -0,0 +1,54 @@
+// Copyright 2020 Google LLC
+
+struct UBO
+{
+	float4x4 projection;
+	float4x4 model;
+	float4 lightPos;
+	float tessAlpha;
+	float tessStrength;
+};
+
+cbuffer ubo : register(b1) { UBO ubo; }
+
+Texture2D textureDisplacementMap : register(t2);
+SamplerState samplerDisplacementMap : register(s2);
+
+struct HSOutput
+{
+[[vk::location(2)]]	float4 Pos : POSITION;
+[[vk::location(0)]] float3 Normal : NORMAL0;
+[[vk::location(1)]] float2 UV : TEXCOORD0;
+};
+
+struct ConstantsHSOutput
+{
+    float TessLevelOuter[3] : SV_TessFactor;
+    float TessLevelInner : SV_InsideTessFactor;
+};
+
+struct DSOutput
+{
+	float4 Pos : SV_POSITION;
+[[vk::location(0)]] float3 Normal : NORMAL0;
+[[vk::location(1)]] float2 UV : TEXCOORD0;
+[[vk::location(2)]] float3 EyesPos : POSITION0;
+[[vk::location(3)]] float3 LightVec : TEXCOORD1;
+};
+
+[domain("tri")]
+DSOutput main(ConstantsHSOutput input, float3 TessCoord : SV_DomainLocation, const OutputPatch<HSOutput, 3> patch)
+{
+	DSOutput output = (DSOutput)0;
+	output.Pos = (TessCoord.x * patch[0].Pos) + (TessCoord.y * patch[1].Pos) + (TessCoord.z * patch[2].Pos);
+	output.UV = mul(TessCoord.x, patch[0].UV) + mul(TessCoord.y, patch[1].UV) + mul(TessCoord.z, patch[2].UV);
+	output.Normal = TessCoord.x * patch[0].Normal + TessCoord.y * patch[1].Normal + TessCoord.z * patch[2].Normal;
+
+	output.Pos.xyz += normalize(output.Normal) * (max(textureDisplacementMap.SampleLevel(samplerDisplacementMap, output.UV.xy, 0).a, 0.0) * ubo.tessStrength);
+
+	output.EyesPos = output.Pos.xyz;
+	output.LightVec = normalize(ubo.lightPos.xyz - output.EyesPos);
+
+	output.Pos = mul(ubo.projection, mul(ubo.model, output.Pos));
+	return output;
+}