Render basic geometry

Added GraphicsContext, SwapChain, Buffer, VertexBuffer, IndexBuffer and a basic DX11 implementation.

Sandbox/content/basicShader.hlsl

@@ -0,0 +1,25 @@
+struct VS_IN
+{
+    float3 Position : POSITION;
+    float4 Color    : COLOR;
+};
+
+struct PS_IN
+{
+    float4 Position : SV_POSITION;
+    float4 Color    : COLOR;
+};
+
+PS_IN VS(VS_IN input)
+{
+    PS_IN output;
+    output.Position = float4(input.Position, 1);
+    output.Color = input.Color;
+    
+    return output;
+}
+
+float4 PS(PS_IN input) : SV_TARGET
+{
+    return input.Color;
+}