You definitely can return array of configurations from your webpack.config file. But it's not an optimal solution if you just want a copy of artifacts to be in the folder of your project's documentation, since it makes webpack build your code twice doubling the overall time to build.
In this case I'd recommend to use the FileManagerWebpackPlugin plugin instead:
const FileManagerPlugin = require('filemanager-webpack-plugin');
// ...
plugins: [
// ...
new FileManagerPlugin({
onEnd: {
copy: [{
source: './dist/*.*',
destination: './public/',
}],
},
}),
],