update TODO

TODO

@@ -25,14 +25,16 @@ External:
 Features:
 
 * resolved:
-  - cache
-  - IDN
+  - IDN (?)
   - DNSSEC
   - LLMNR
   - mDNS/DNS-SD
   - DNS-SD service registration from socket units
   - port sd-resolve to direct bus calls
   - nss module: fallback to glibc dns modules if resolved cannot be contacted
+  - edns0 + dname
+  - cname on PTR (?)
+  - negative caching
 
 * Allow multiple ExecStart= for all Type= settings, so that we can cover rescue.service nicely