README.rst: add hint on how to use casync on host [PR #161]
README.rst: add hint on how to use casync on host
[PR #161]

Signed-off-by: Yang Hongbo <d045e22c33778eb4582053f9a1abe7d4b888df5a@iotpi.io>

rauc/meta-rauc,rauc/meta-rauc,rauc/meta-rauc,rauc/meta-rauc