Correct Markdown link syntax in Oncilla example :shake_fist_at_left:

Author: breckenedge

sample/README.md

@@ -7,7 +7,7 @@ incoming messages from Oncilla. It can be used as a development aid while implem
 
 1. Run `npm install`
 2. Run `npm run start-server`
-3. From a WebSocket client, e.g. (Simple WebSocket Client)[https://chrome.google.com/webstore/detail/simple-websocket-client/pfdhoblngboilpfeibdedpjgfnlcodoo?hl=en] connect to `localhost:8020`.
+3. From a WebSocket client, e.g. [Simple WebSocket Client](https://chrome.google.com/webstore/detail/simple-websocket-client/pfdhoblngboilpfeibdedpjgfnlcodoo?hl=en) connect to `localhost:8020`.
 4. Send a sample message, such as:
 
 ```json