Update OpenBSD's README tip
Update OpenBSD's README tip

I have made an OpenBSD port. It is now available for -current.
casimir/kakoune,danr/kakoune,Somasis/kakoune,Somasis/kakoune,jkonecny12/kakoune,alexherbo2/kakoune,mawww/kakoune,lenormf/kakoune,Somasis/kakoune,danr/kakoune,jkonecny12/kakoune,jkonecny12/kakoune,danr/kakoune,Somasis/kakoune,lenormf/kakoune,alexherbo2/kakoune,mawww/kakoune,alexherbo2/kakoune,jkonecny12/kakoune,lenormf/kakoune,alexherbo2/kakoune,mawww/kakoune,casimir/kakoune,mawww/kakoune,danr/kakoune,casimir/kakoune,casimir/kakoune,lenormf/kakoune