CHANGELOG entry for network cidr filters

CHANGELOG.md

@@ -4,6 +4,11 @@
   octodns.com.octodns.com
 * Fixed issues with handling of chunking large TXT values for providers that use
   the in-built `rrs` method
+* NetworkValueAllowlistFilter/NetworkValueRejectlistFilter added to
+  processors.filter to enable filtering A/AAAA records based on value. Can be
+  useful if you have records with non-routable values in an internal copy of a
+  zone, but want to exclude them when pushing the same zone publically (split
+  horizon)
 * ExcludeRootNsChanges processor that will error (or warn) if plan includes a
   change to root NS records
 * Include the octodns special section info in Record __repr__, makes it easier