Document default value for Nickname

doc/tor.1.txt

@@ -2061,6 +2061,8 @@ is non-zero):
 [[Nickname]] **Nickname** __name__::
     Set the server's nickname to \'name'. Nicknames must be between 1 and 19
     characters inclusive, and must contain only the characters [a-zA-Z0-9].
+    If not set, **Unnamed** will be used. Relays can always be uniquely identified
+    by their identity fingerprints.
 
 [[NumCPUs]] **NumCPUs** __num__::
     How many processes to use at once for decrypting onionskins and other

src/config/torrc.minimal.in-staging

@@ -100,7 +100,7 @@
 ## A handle for your relay, so people don't have to refer to it by key.
 ## Nicknames must be between 1 and 19 characters inclusive, and must
 ## contain only the alphanumeric characters (a-z, A-Z, 0-9). No unicode,
-## no emoji.
+## no emoji. If not set, "Unnamed" will be used.
 #Nickname ididnteditheconfig
 
 ## Define these to limit how much relayed traffic you will allow. Your

src/config/torrc.sample.in

@@ -106,6 +106,7 @@
 ## A handle for your relay, so people don't have to refer to it by key.
 ## Nicknames must be between 1 and 19 characters inclusive, and must
 ## contain only the characters [a-zA-Z0-9].
+## If not set, "Unnamed" will be used.
 #Nickname ididnteditheconfig
 
 ## Define these to limit how much relayed traffic you will allow. Your