message: fix(package.json): fix "pack" script.
diff: "lint:demo": "ng lint ng-chartist-demo",
  "lint:lib": "ng lint ng-chartist",
  "ng": "ng",
  - "pack": "cd dist/ng-chartist && yarn pack",
  + "pack": "cd dist/ng-chartist-lib && yarn pack",
  "package": "yarn run build:lib && yarn run pack",
  "postgh-pages": "git add . && git commit -m 'chore(*): build demo and docs' && git push && git checkout master",
  "start": "ng serve ng-chartist-demo",
  