vue.config.js - use ES modules in docs

[Mikilll94]

What problem does this feature solve?

Right now in the docs vue.config.js file is using CommonJS syntax, like i.e. here
https://cli.vuejs.org/config/#global-cli-config
https://cli.vuejs.org/guide/webpack.html#simple-configuration

Can you change these examples to use ES modules syntax? ES modules is a more modern and better syntax. Also Visual Studio Code is highlighting this CommonJS syntax with a suggestion to convert it to ES modules.

What does the proposed API look like?

Use ES modules syntax in the docs.

[fangbinwei]

I think CLI needs support vue.config.mjs first. Since CLI generates configuration files like babel.config.js with CommonJS by default, maybe it is not a good time to change the document now.

[linghengqian]

This issue was resolved at #6405 and should be closed.