* HACKING.md: add a note on using Homebrew to install readline on OSX
* HACKING.md: add a note on using Homebrew to install readline on OSX

Thanks to Daniel Trebbien for the tip

ptoscano/augeas,mchf/augeas,mlichvar/augeas,dafugg/augeas,kunkku/augeas,mchf/augeas,pevalme/augeas,mlichvar/augeas,pevalme/augeas,mlichvar/augeas,kunkku/augeas,manandbytes/augeas,lutter/augeas,lutter/augeas,dafugg/augeas,ptoscano/augeas,kunkku/augeas,ptoscano/augeas,lutter/augeas,hercules-team/augeas,hercules-team/augeas,manandbytes/augeas,dafugg/augeas,pevalme/augeas