An index can essentially be considered a database that contains all of your searchable content. By default, it will store everything in a field called `Content`, which is queried to find your search results. To create an index that you can query, you can define it like so:
You can also skip listing all searchable fields, and have the index figure it out automatically via `addAllFulltextFields()`. This will add any database fields that are `instanceof DBString` to the index. Use this with caution, however, as you may inadvertently return sensitive information - it is often safer to declare your fields explicitly.