[tor-project] I figured out v3 onion client auth and wrote a blog post

[Matt Traudt]

See it here:

https://matt.traudt.xyz/p/FgbdRTFr.html or
http://mattttttssi4lhud.onion/p/FgbdRTFr.html or
http://zfob4nth675763zthpij33iq4pz5q4qthr3gydih4qbdiwtypr2e3bqd.onion/p/FgbdRTFr.html

While doing so I opened two tickets:

Document the max number of v3 client auths I can make
https://trac.torproject.org/projects/tor/ticket/29134

Failing to connect to a v3 onion service with client auth produces
really long lines in log
https://trac.torproject.org/projects/tor/ticket/29135

Sometimes it seems like advanced features aren't documented very well,
so I thought I'd write down what I figured out. I encourage Tor to use
this in whatever way makes sense.

Matt