alice.conf: Add some comments about section usage

etc/alice-lg/alice.example.conf

@@ -83,8 +83,10 @@ routes_accepted_page_size = 250
 routes_not_exported_page_size = 250
 
 [rejection_reasons]
-# a pair of a large BGP community value and a string to signal the processing
-# results of route filtering
+# BGP communities which, when present on a prefix represent the route as having
+# been filtered out.
+# Additionally, communities for searching and descriptions should be listed in
+# the [bgp_communities] section of this configuration.
 9033:65666:1 = An IP Bogon was detected
 9033:65666:2 = Prefix is longer than 64
 9033:65666:3 = Prefix is longer than 24
@@ -140,7 +142,8 @@ unknown     = 23042:1000:2
 invalid     = 23042:1000:4-*
 
 
-# Define other known bgp communities
+# Define known bgp communities which should be recognized and described in the
+# Alice web UI
 [bgp_communities]
 1:23 = some tag
 9033:65666:1 = ip bogon detected