Draft: Resolve #3468269 "Simplify tree"

Closes #3468269

docs/data-model.md

@@ -311,17 +311,36 @@ Example, that populates only the two "marquee" `component instance`s in the _tre
 ```json
 {
   "uuid-root-2": {
-    "text": {
-      "sourceType": "dynamic",
-      "expression": "ℹ︎␜entity:node:article␝title␞␟value"
+    "component": "provider:two-col",
+    "slots": {
+      "firstColumn": [
+        "uuid4-author1",
+        "uuid2-submitted",
+      ],
+      "secondColumn": [
+        "uuid5-author2",
+      ]
     }
   },
   "uuid-root-3": {
-    "text": {
-      "sourceType": "static:field_item:string",
-      "value": "Hello, world!",
-      "expression": "ℹ︎string␟value"
+    "component": "provider:marquee",
+    "slots": {
+      "content": [
+        "uuid4-author3",
+      ]
     }
+  },
+  "uuid4-author1": {
+    "component" : "provider:no-slots"
+  },
+  "uuid2-submitted": {
+    "component" : "provider:no-slots"
+  },
+  "uuid5-author2": {
+    "component" : "provider:no-slots"
+  },
+  "uuid4-author3" : {
+    "component": "provider:no-slots"
   }
 }
 ```