chore(README-mac.md): put up a notice about #247  [ci skip]
chore(README-mac.md): put up a notice about #247  [ci skip]

Closes #247.

Prcuvu/librime,rime/librime,rime/librime,Prcuvu/librime,rime/librime,Prcuvu/librime,Prcuvu/librime,Prcuvu/librime,rime/librime