Add solution for "The default website isn't defined. Set the website and try again." in Magento deployments

docs/hypernode-deploy/applications/config-for-magento-2.md

@@ -17,6 +17,19 @@ return $configuration;
 
 By using the Magento2 ApplicationTemplate, a bunch of default configuration gets set in Hypernode Deploy, and should work out-of-the-box for most magento 2 stores.
 
+## Known issues
+
+### Error: The default website isn't defined. Set the website and try again.
+
+When this error is thrown, please assure the app/etc/config.php has the keys 'scopes' and 'themes'. This is needed for the deployment software to be aware of what themes are installed without a database present (during pipeline run).
+
+You can fix this by running the following command and then commiting the result to your codebase:
+
+```
+$ php bin/magento app:config:dump scopes themes
+Done. Config types dumped: scopes, themes
+```
+
 ## Advanced
 
 However, for advanced configurations you can override most steps and variables set my Hypernode Deploy: