deleted HACKING.md, because it's outdated and new documentation is in doc/develop.md
deleted HACKING.md, because it's outdated and new documentation is in doc/develop.md

chadmiller/securedrop,conorsch/securedrop,pwplus/securedrop,jaseg/securedrop,heartsucker/securedrop,jrosco/securedrop,GabeIsman/securedrop,jaseg/securedrop,GabeIsman/securedrop,ehartsuyker/securedrop,micahflee/securedrop,kelcecil/securedrop,conorsch/securedrop,chadmiller/securedrop,pwplus/securedrop,jeann2013/securedrop,ageis/securedrop,jeann2013/securedrop,harlo/securedrop,jrosco/securedrop,pwplus/securedrop,jaseg/securedrop,ehartsuyker/securedrop,jaseg/securedrop,heartsucker/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,jrosco/securedrop,chadmiller/securedrop,pwplus/securedrop,harlo/securedrop,ageis/securedrop,chadmiller/securedrop,conorsch/securedrop,garrettr/securedrop,micahflee/securedrop,heartsucker/securedrop,jrosco/securedrop,ehartsuyker/securedrop,jaseg/securedrop,pwplus/securedrop,harlo/securedrop,garrettr/securedrop,jeann2013/securedrop,GabeIsman/securedrop,GabeIsman/securedrop,ageis/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,garrettr/securedrop,harlo/securedrop,jrosco/securedrop,kelcecil/securedrop,conorsch/securedrop,jeann2013/securedrop,harlo/securedrop,jaseg/securedrop,GabeIsman/securedrop,garrettr/securedrop,pwplus/securedrop,harlo/securedrop,jeann2013/securedrop,conorsch/securedrop,micahflee/securedrop,kelcecil/securedrop,kelcecil/securedrop,ageis/securedrop,micahflee/securedrop,chadmiller/securedrop,kelcecil/securedrop,jeann2013/securedrop,kelcecil/securedrop,chadmiller/securedrop,jrosco/securedrop,ehartsuyker/securedrop,GabeIsman/securedrop