Я получил ошибку при запуске JAMstack :
$ yarn start
yarn run v1.19.1
$ gulp server
[05:04:13] Using gulpfile /jamstack.org/gulpfile.js
[05:04:13] Task 'server' is not in your gulpfile
[05:04:13] Please check the documentation for proper gulpfile formatting
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
Как решить эту проблему?