feat: nested collections (#680)

packages/docs/content/docs/collection-types.mdx

@@ -311,6 +311,9 @@ collections:
     nested:
       depth: 100 # max depth to show in the collection tree
       summary: '{{title}}' # optional summary for a tree node, defaults to the inferred title field
+      # adding a path object allows editing the path of entries
+      # moving an existing entry will move the entire sub tree of the entry to the new location
+      path: { widget: string, index_file: 'index' }
     fields:
       - label: Title
         name: title
@@ -318,9 +321,6 @@ collections:
       - label: Body
         name: body
         widget: markdown
-    # adding a meta object with a path property allows editing the path of entries
-    # moving an existing entry will move the entire sub tree of the entry to the new location
-    meta: { path: { widget: string, label: 'Path', index_file: 'index' } }
 ```
 
 ```js
@@ -334,7 +334,11 @@ collections:
       "create": true,
       "nested": {
         "depth": 100,
-        "summary": "{{title}}"
+        "summary": "{{title}}",
+        "path": {
+          "label": "Path",
+          "index_file": "index"
+        }
       },
       "fields": [
         {
@@ -347,14 +351,7 @@ collections:
           "name": "body",
           "widget": "markdown"
         }
-      ],
-      "meta": {
-        "path": {
-          "widget": "string",
-          "label": "Path",
-          "index_file": "index"
-        }
-      }
+      ]
     }
   ]
 }