add a blurb to the docs about building sccache-dist binaries
add a blurb to the docs about building sccache-dist binaries

mozilla/sccache,glandium/sccache,glandium/sccache,mozilla/sccache,mozilla/sccache,luser/sccache2,glandium/sccache,luser/sccache2,luser/sccache2,glandium/sccache,luser/sccache2