docs: Improve wl_touch protocol docs
docs: Improve wl_touch protocol docs

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mchalupa/wayland,abooij/wayland,tulcod/wayland,tulcod/wayland,sir-murray/wayland,abooij/wayland,sir-murray/wayland,eyolfson/wayland,bitfactor/wayland,bitfactor/wayland,eyolfson/wayland,tulcod/wayland,eyolfson/wayland,mchalupa/wayland,bitfactor/wayland,abooij/wayland,sir-murray/wayland,mchalupa/wayland