Improve MyFamily docs, based on patch from nusenu

Closes ticket 22223

doc/tor.1.txt

@@ -1732,14 +1732,17 @@ is non-zero):
     If we have more onionskins queued for processing than we can process in
     this amount of time, reject new ones. (Default: 1750 msec)
 
-[[MyFamily]] **MyFamily** __node__::
-    Declare that this Tor server is controlled or administered by a group or
-    organization identical or similar to that of the other servers, defined by
-    their identity fingerprints. This option can be repeated many times, for
-    multiple families. When two servers both declare that they are in the
+[[MyFamily]] **MyFamily** __fingerprint__,__fingerprint__,...::
+    Declare that this Tor relay is controlled or administered by a group or
+    organization identical or similar to that of the other relays, defined by
+    their (possibly $-prefixed) identity fingerprints.
+    This option can be repeated many times, for
+    convenience in defining large families: all fingerprints in all MyFamily
+    lines are merged into one list.
+    When two relays both declare that they are in the
     same \'family', Tor clients will not use them in the same circuit. (Each
-    server only needs to list the other servers in its family; it doesn't need to
-    list itself, but it won't hurt.) Do not list any bridge relay as it would
+    relay only needs to list the other servers in its family; it doesn't need to
+    list itself, but it won't hurt if it does.) Do not list any bridge relay as it would
     compromise its concealment. +
  +
     When listing a node, it's better to list it by fingerprint than by