Add release notes for 4.6.0 and clarify documentation

Author: oschwald

HISTORY.rst

@@ -4,6 +4,15 @@
 History
 -------
 
+4.6.0 (2022-06-21)
+++++++++++++++++++
+
+* The ``AddressNotFoundError`` class now has an ``ip_address`` attribute
+  with the lookup address and ``network`` property for the empty network
+  in the database containing the IP address. These are only available
+  when using a database, not the web service. Pull request by illes.
+  GitHub #130.
+
 4.5.0 (2021-11-18)
 ++++++++++++++++++
 

geoip2/errors.py

@@ -23,14 +23,16 @@ class AddressNotFoundError(GeoIP2Error):
 
     .. attribute:: ip_address
 
-      The IP address used in the lookup.
+      The IP address used in the lookup. This is only available for database
+      lookups.
 
       :type: str
 
     .. attribute:: network
 
       The network associated with the error. In particular, this is the
-      largest network where no address would be found.
+      largest network where no address would be found. This is only
+      available for database lookups.
 
       :type: ipaddress.IPv4Network or ipaddress.IPv6Network