Added sounds of steps (raw version)

build/engine/sounds/actor/step/default1.ogg

build/engine/sounds/actor/step/default2.ogg

build/engine/sounds/actor/step/default3.ogg

build/engine/sounds/actor/step/default4.ogg

build/engine/sounds/actor/step/earth1.ogg

build/engine/sounds/actor/step/earth2.ogg

build/engine/sounds/actor/step/earth3.ogg

build/engine/sounds/actor/step/earth4.ogg

build/engine/sounds/actor/step/grass1.ogg

build/engine/sounds/actor/step/grass2.ogg

build/engine/sounds/actor/step/grass3.ogg

build/engine/sounds/actor/step/grass4.ogg

build/engine/sounds/actor/step/gravel1.ogg

build/engine/sounds/actor/step/gravel2.ogg

build/engine/sounds/actor/step/metal_plate1.ogg

build/engine/sounds/actor/step/metal_plate2.ogg

build/engine/sounds/actor/step/metal_plate3.ogg

build/engine/sounds/actor/step/metal_plate4.ogg

build/engine/sounds/actor/step/new_wood1.ogg

build/engine/sounds/actor/step/new_wood2.ogg