puck doc tweaks

info/Troubleshooting.md

@@ -192,6 +192,7 @@ To enter normal mode, just:
 |-------|----|
 | Pico/WiFi | Unplug from USB and re-plug, without pressing the button. |
 | Espruino Board | Press and release **RST** while **BTN1** is not pressed. |
+| Puck.js | Remove and re-insert the battery |
 
 ## When I upload code, some characters are being lost
 

puck/Puck.js Web Bluetooth.md

@@ -322,6 +322,11 @@ and we could just handle it directly.
 That's what you can do with `Puck.connect(callback)`. Once connected it calls the `callback`
 function with the connection, which you can then use to send and receive data.
 
+**Note:** You can't use `Puck.connect` and `Puck.write/eval` on the same
+connection at the same time. If you want to write to a Puck after having 
+used `Puck.connect`, you need to use `connection.write` and handle 
+any response in the `connection.on("data",` handler.
+
 Try the example below:
 
 ```HTML_demo_link