v2.0 not find 'package.json'

OS : ubuntu 18.04.1 LTS webchat version: v2.0 (64bits) step1 : download the webchat installation package from git; step2 : tar -zxvf *.tar.gz step3 : npm install && npm start

...... not find 'package.json' ...... note: after step 2,i also don't find the file 'package.json'