Add README.md to linux release tarballs
Add README.md to linux release tarballs

fix #8160

DigitalPandacoin/pandacoin,DigitalPandacoin/pandacoin,DigitalPandacoin/pandacoin,DigitalPandacoin/pandacoin,peercoin/peercoin,peercoin/peercoin,peercoin/peercoin,peercoin/peercoin,DigitalPandacoin/pandacoin,peercoin/peercoin,peercoin/peercoin,DigitalPandacoin/pandacoin