v2.0 not find 'package.json'

[guoyanzhang0817]

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'