Update Index data

[ruipppinho]

Hi, I am currently investigating rdf storage and query alternatives and from what I understand, with QLever the data needs to be indexed before it can be queried.
So, I have two questions about this process:

Is it possible to index data from a zip file containing multiple Turtle (.ttl) files?
Additionally, if I am trying to use only one instance of QLever backend, is it possible to add new data to the existing index data, or would I need to delete the index and create a new one each time?

Best regards,
Rui