add README
add README

Signed-off-by: Sven Verdoolaege <e5350bbed4977f5eb8ae1dc6abd9ae59d21ace75@kotnet.org>

PollyLabs/isl,Meinersbur/isl,SaberMod/isl-current,inducer/isl-mirror,serge-sans-paille/isl,simbuerg/isl,evaautomation/isl,epowers/isl,pierrotdelalune/isl,UBERTC/isl,Distrotech/isl,SaberMod/isl-current,tobig/isl,Distrotech/isl,cfx-next/toolchain_isl-upstream,VanirLLVM/toolchain_isl,cfx-next/toolchain_isl-upstream,BobSaget-Mod/libisl,evaautomation/isl,crossbuild/isl,BenzoSM/isl,epowers/isl,UBERTC/isl,pierrotdelalune/isl,tobig/isl,serge-sans-paille/isl,nicolasvasilache/isl,KangDroidSMProject/ISL,abduld/isl,BenzoSM/isl,tobig/isl,pierrotdelalune/isl,simbuerg/isl,VanirLLVM/toolchain_isl,BobSaget-Mod/libisl,evaautomation/isl,BobSaget-Mod/libisl,simbuerg/isl,jleben/isl,pierrotdelalune/isl,inducer/isl-mirror,crossbuild/isl,evaautomation/isl,BenzoSM/isl,nicolasvasilache/isl,UBERTC/isl,simbuerg/isl,KangDroidSMProject/ISL,cfx-next/toolchain_isl-upstream,KangDroidSMProject/ISL,nicolasvasilache/isl,BobSaget-Mod/libisl,crossbuild/isl,inducer/isl-mirror,PollyLabs/isl,PollyLabs/isl,Meinersbur/isl,inducer/isl-mirror,SaberMod/isl-current,abduld/isl,simbuerg/isl,inducer/isl-mirror,tobig/isl,UBERTC/isl,Distrotech/isl,nicolasvasilache/isl,jleben/isl,BenzoSM/isl,epowers/isl,epowers/isl,VanirLLVM/toolchain_isl,BobSaget-Mod/libisl,nicolasvasilache/isl,Meinersbur/isl,serge-sans-paille/isl,abduld/isl,VanirLLVM/toolchain_isl,serge-sans-paille/isl,KangDroidSMProject/ISL,jleben/isl,jleben/isl,cfx-next/toolchain_isl-upstream,pierrotdelalune/isl,Distrotech/isl,serge-sans-paille/isl,epowers/isl,crossbuild/isl,PollyLabs/isl,SaberMod/isl-current,BenzoSM/isl,jleben/isl,cfx-next/toolchain_isl-upstream,VanirLLVM/toolchain_isl,PollyLabs/isl,Distrotech/isl,Meinersbur/isl,abduld/isl,KangDroidSMProject/ISL