Add config example that supports `ssh black`

docs/ssh-over-tor.md

@@ -4,6 +4,37 @@ One of the best ways to maintain your anonymity on Tilde Black is
 to connect to ssh using tor. Your home IP address will be hidden
 from other users.
 
+## Recommended: ~/.ssh/config
+
+Add something like this in your `~/.ssh/config`:
+
+```
+# tilde.black
+
+# create entries like these for all the usernames you want to use:
+Host black-aaa
+    User aaa
+
+Host black-bbb
+    User bbb
+
+Host black*
+    Port 2222
+    # always connect over Tor
+    HostName black6kfjetfuzaeozz7fs53whh7xtd4e27telrf5fg5kgdt5ah5plad.onion
+    ProxyCommand nc -x 127.0.0.1:9050 -X 5 %h %p
+    VerifyHostKeyDNS no
+    # use a key created just for tilde.black
+    IdentityFile ~/.ssh/id_black
+    # optionally, set a default username
+    User ccc
+```
+
+Then connect with `ssh black` or `ssh black-<username>`. This way you can never accidentally connect through plain TCP.
+
+Requirements for this to work are that the `tor` daemon is running and netcat (`nc`) is installed.
+
+
 ## Easy Mode
 
 Before trying the rest of this document, you can try the easy-mode