Currently, the web results reside in a separate core from the “standard” VuFind data, they use a different schema for searching and indexing. If you want a fully integrated result list, it would be necessary to crosswalk the web data into the biblio index and adjust the record driver – possible, but not a completely simple job.
If you don’t require a fully integrated list but just want to see some web results on the same screen as the standard results, you have two options:
1.) You could use the special “Combined” module of VuFind, configured to show Solr and SolrWeb side-by-side: https://vufind.org/wiki/vufind2:combining_search_types
2.) You could use the “WebResults” recommendation module (which can be activated in searches.ini) to display top web results above or beside the standard results when doing a regular search.
I hope this is helpful – please let me know if you need me to elaborate on any of these options.