Add mention of breaking change

Author: eborden

CHANGELOG.md

@@ -4,10 +4,12 @@
   [5b0987197fe2ed7beddd7b2096522d624e71151e](https://github.com/haskell/network/commit/5b0987197fe2ed7beddd7b2096522d624e71151e)
 * Improved FreeBSD portability for Control Messages and tests
   [#452](https://github.com/haskell/network/pull/452)
-* Added `sendMsg` and `recvMsg` APIs
+* Support `sendMsg` and `recvMsg`
   [#433](https://github.com/haskell/network/pull/433)
   [#445](https://github.com/haskell/network/pull/445)
   [#451](https://github.com/haskell/network/pull/451)
+    * Added `sendMsg` and `recvMsg` APIs
+    * Redefined `SocketOption` as pattern synonym
 * Implement total Show functions for SockAddr
   [#441](https://github.com/haskell/network/pull/441)
 * Improve portability changing `u_int32_t` to `uint32_t`.