[docs] Add release notes for removing -usehd

jnewbery · jnewbery · commit 7ac911afe7ae · 2018-09-26T17:32:39.000-04:00
diff --git a/doc/release-notes-14282.md b/doc/release-notes-14282.md
@@ -0,0 +1,6 @@
+Low-level RPC changes
+----------------------
+
+`-usehd` was removed in version 0.16. From that version onwards, all new
+wallets created are hierarchical deterministic wallets. Version 0.18 makes
+specifying `-usehd` invalid config.
