feat: Multible Documents(PDF) for Embedding

[kalle07]

Problem
at the moment only talk with one document (ok two) but if the chat is closed the document must be every time i want use it, again indexed and embeded

Success Criteria
so i want a library where i have maybe 20 books, i can seprate add or remove and they are permanently embedded.
so if i talk with one or two documents of these list , i only choose them, thats all.

Additional context
i have the assumption that documents bigger 100-200 pages are not embedded (10min nothing happend), smaller is ok ~30sec

[kalle07]

no one need that ?