What is the preferred method to save a file, be it turtle or an image or a video etc. on a solid POD?
The documentation at https://linkeddata.github.io/rdflib.js/doc/Fetcher.html is, as stated in the readme, of limited usefulness in its current state.
To add to the accepted answer, @inrupt/solid-client also has support for storing plain files on a Pod: https://docs.inrupt.com/developer-tools/javascript/client-libraries/tutorial/read-write-files/
(Although if you plan on writing Turtle, it's probably best to use its specialised API.)
