[#92][Doc] add missing docu and edit docu

include/vkcv/Core.hpp

include/vkcv/DescriptorWrites.hpp

include/vkcv/FeatureManager.hpp

include/vkcv/ShaderStage.hpp

modules/rtx/include/vkcv/rtx/ASManager.hpp

modules/rtx/include/vkcv/rtx/RTX.hpp

modules/rtx/include/vkcv/rtx/RTXExtensions.hpp

modules/rtx/src/vkcv/rtx/ASManager.cpp

modules/rtx/src/vkcv/rtx/RTX.cpp

modules/rtx/src/vkcv/rtx/RTXExtensions.cpp

modules/scene/src/vkcv/scene/Scene.cpp

modules/shader_compiler/src/vkcv/shader/GLSLCompiler.cpp

projects/rtx/resources/shaders/ambientOcclusion.rchit

projects/rtx/resources/shaders/ambientOcclusion.rgen

projects/rtx/src/main.cpp

projects/rtx/src/teapot.hpp

src/vkcv/Context.cpp

src/vkcv/Core.cpp

src/vkcv/DescriptorManager.cpp

src/vkcv/FeatureManager.cpp