Persistence preset: Tor Browser security level

This was, by far, the most requested feature in the 2020 user survey.
#18006 (closed) and 3.14.1 would have benefited from this.
On the other hand, our personas are probably fine with having JavaScript enabled by default. Most probably they actually need it.

Edited Jul 27, 2021 by sajolida

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information