Multi-site compatibility

[timkelty]

I have a Craft 3 multi-site with separate rev manifests per-site.

Would be great if in my config I could do

return [
    'siteA' => [
        'manifestPath' => 'sites/siteA/public/assets/manifest.json',
        'assetsBasePath' => 'sites/siteA/public/assets',
        'assetUrlPrefix' => getenv('ASSET_URL_PREFIX'),
    ],
    'siteB' => [
        'manifestPath' => 'sites/siteB/public/assets/manifest.json',
        'assetsBasePath' => 'sites/siteB/public/assets',
        'assetUrlPrefix' => getenv('ASSET_URL_PREFIX'),
    ],
];```