Changes

After long discussing the best way to publish networks with Stockfish<ref>https://github.com/official-stockfish/Stockfish/issues/3030 Improve dealing with the default net? by Vondele · Issue ##3030 · official-stockfish/Stockfish · GitHub], August 19, 2020</ref>, the developing team decided to embed the default network into Stockfish binaries, making sure NNUE always works as well as bringing more convenience to users.