Merge pull request #52 from pezcode/demo-light

CMakeLists.txt

liblava-demo/light.cpp

liblava/app/imgui.cpp

liblava/block/render_pass.hpp

liblava/block/subpass.cpp

liblava/resource/image.cpp

res/lamp/gen_spirv.bat

res/lamp/gen_spirv.sh

res/lamp/lamp.frag.u32

res/lamp/lamp.vert.u32

res/light/data.inc

res/light/gbuffer.frag

res/light/gbuffer.fragment.spirv

res/light/gbuffer.vert

res/light/gbuffer.vertex.spirv

res/light/gen_spirv.bat

res/light/gen_spirv.sh

res/light/lighting.frag

res/light/lighting.fragment.spirv

res/light/lighting.vert