Exception when using not default output_path

[zorn-v]

Steps to reproduce:

1. Run

composer create symfony/skeleton
cd skeleton
composer req encore twig maker doctrine/annotations
./bin/console make:cont Test

2. Add {{ encore_entry_link_tags('app') }} in templates/base.html.twig
3. Change output_path in config/packages/webpack_encore.yaml to %kernel.project_dir%/public/build/default
4. Change paths in webpack.config.js

Encore
    // directory where compiled assets will be stored
    .setOutputPath('public/build/default')
    // public path used by the web server to access the output path
    .setPublicPath('/build/default')

5. Run npm i && npm run build
6. Run web server (e.g. php -S 8888 -t public) and open http://localhost:8888/test

And you get exeption like this
An exception has been thrown during the rendering of a template ("Asset manifest file "/var/www/html/public/build/manifest.json" does not exist.").

[zorn-v]

You also need to change framework.assets.json_manifest_path config value in such case

[weaverryan]

I've added a note about this to the docs. Thanks!