Next js 12 July 8, 2019 16 32 64 128 Next js 12 middleware Next js 12 to 13 Next js 12.3 4 Next js 12 release date Next js 12 to 14 migration Next js 12 vs 14 Next js 12 to 13 migration Next js 12 node version Next js 12 to 14 Next js 12.3 4 exploit Next js 12 install