按照webpack5文档上修改，可还是跑不起来
× ｢wds｣: Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.

• configuration.devtool should match pattern “^(inline-|hidden-|eval-)?(nosources-)?(cheap-(module-)?)?source-map$”.
  BREAKING CHANGE since webpack 5: The devtool option is more strict.
  Please strictly follow the order of the keywords in the pattern.
  npm ERR! code ELIFECYCLE
  npm ERR! errno 1
  npm ERR! vue-ssr-tech@1.0.0 dev:client: cross-env NODE_ENV=development webpack-dev-server --config build/webpack.config.client.js
  npm ERR! Exit status 1
  npm ERR!
  npm ERR! Failed at the vue-ssr-tech@1.0.0 dev:client script.
  npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in: