Fix node send api link in blog post

Author: knolleary

_posts/2019-09-30-version-1-0-released.md

@@ -30,7 +30,7 @@ but there's plenty to get you started.
 ---
 
  - [Asynchonous message passing](#asynchronous-message-passing)
- - [Node Send API](#asynchronous-message-passing)
+ - [Node Send API](#node-send-api)
  - [Cloning messages](#cloning-messages)
  - [Reorganised palette](#reorganised-palette)
  - [Removed nodes](#removed-nodes)