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/glsl/multithreading/phong.vert

@@ -0,0 +1,39 @@
+#version 450
+
+layout (location = 0) in vec3 inPos;
+layout (location = 1) in vec3 inNormal;
+layout (location = 2) in vec3 inColor;
+
+layout (std140, push_constant) uniform PushConsts 
+{
+	mat4 mvp;
+	vec3 color;
+} pushConsts;
+
+layout (location = 0) out vec3 outNormal;
+layout (location = 1) out vec3 outColor;
+layout (location = 3) out vec3 outViewVec;
+layout (location = 4) out vec3 outLightVec;
+
+void main() 
+{
+	outNormal = inNormal;
+
+	if ( (inColor.r == 1.0) && (inColor.g == 0.0) && (inColor.b == 0.0))
+	{	
+		outColor = pushConsts.color;
+	}
+	else
+	{
+		outColor = inColor;
+	}
+	
+	gl_Position = pushConsts.mvp * vec4(inPos.xyz, 1.0);
+	
+    vec4 pos = pushConsts.mvp * vec4(inPos, 1.0);
+    outNormal = mat3(pushConsts.mvp) * inNormal;
+//	vec3 lPos = ubo.lightPos.xyz;
+vec3 lPos = vec3(0.0);
+    outLightVec = lPos - pos.xyz;
+    outViewVec = -pos.xyz;
+}