Write even more documentation

README.md

@@ -69,6 +69,25 @@ The message format used:
 
 You can use the `MessageSender` class to send messages from the TFW server or event handlers written in Python.
 
-### Web
+### Web – customisable component
 
-in progress...
+... explain iframing and custom Angular components...
+
+### Dashboard
+
+The dashboard is the component that composes all others and organises them into layouts.
+It also exposes a frontend API to dynamically change layouts any time using a message format as such:
+
+```
+{ 
+    "key": "dashboard",
+    "data":
+    {
+        "command": "layout",
+        "layout": ...,
+        "hide_messages": ...
+    }
+}
+```
+
+You can use the `hide_messages` key to hide the message component (sadly it currently still takes up the space it would occupy).