remove unnecessary prints

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
README: Add example command

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
README: fix typo

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
README: polish README little

Signed-off-by: SeongJae Park <sj38.park@gmail.com>