### What problem does this feature solve? https://github.com/vuejs/vue-cli/blob/7f56846a2e54ee5b748232e8b5ae2411a147416d/packages/%40vue/cli-service/lib/commands/serve.js#L180 When enabled, file changes will trigger a full page reload. Not friendly in development. ### What does the proposed API look like? watchContentBase: isProduction <!-- generated by vue-issues. DO NOT REMOVE -->