improve Tor usage documentation

[dawuud]

Using Tahoe-LAFS with Tor needs more thorough and clear documentation for both clients and storage/introducer node operators.

As it stands the current Tahoe docs regarding Tor usage are out of date and don't properly inform users of configuration pitfalls which can cause them to be deanonymized.

Here is my current work in progress to improve documentation... however this is mostly document-driven development wherein I am writing the future docs for the native Tor integration for Tahoe-LAFS:

​https://github.com/david415/tahoe-lafs/tree/tor-i2p-documentation ​https://github.com/david415/tahoe-lafs/blob/tor-i2p-documentation/docs/anonymity-configuration.rst ​https://github.com/david415/tahoe-lafs/blob/tor-i2p-documentation/docs/anonymity-roadmap.rst

However here I attempt to provide clear and complete documentation of the "olde way of using Tor + Tahoe-LAFS together" using torsocks :

​https://github.com/david415/tahoe-lafs/blob/tor-i2p-documentation/docs/anonymity-configuration.rst#torsocks-the-old-way-of-configuring-tahoe-lafs-to-use-tor

During a Tahoe-LAFS cryptoparty at Noisebridge we learned that documentation is a bit lacking with regard to configuring a Tahoe-LAFS storage node which is only accessible via Tor Hidden Services.