Make hacking bootstrapping instructions more explicit (#1437)
Make hacking bootstrapping instructions more explicit (#1437)

Signed-off-by: Shon Feder <ea1e9e869ba967b9537eb0b16fe47f610d2cc997@gmail.com>
janestreet/jbuilder,dra27/jbuilder,dra27/jbuilder,dra27/jbuilder,dra27/jbuilder,janestreet/jbuilder,janestreet/jbuilder,dra27/jbuilder,janestreet/jbuilder,janestreet/jbuilder,janestreet/jbuilder,dra27/jbuilder