prettier: Turn down verbosity of output.
prettier: Turn down verbosity of output.

By default, `prettier` prints the name of every file, plus the
time in milliseconds it apparently took to process it.  Cut those
488 lines of output.

vishwesh3/zulip-mobile,vishwesh3/zulip-mobile,vishwesh3/zulip-mobile,vishwesh3/zulip-mobile