feat: nested collections (#680)

packages/core/dev-test/backends/proxy/_nested_pages/authors/author-1/index.md

@@ -0,0 +1,5 @@
+---
+title: An Author
+---
+
+Author details go here!.

packages/core/dev-test/backends/proxy/_nested_pages/authors/index.md

@@ -0,0 +1,3 @@
+---
+title: Authors
+---

packages/core/dev-test/backends/proxy/_nested_pages/index.md

@@ -0,0 +1,3 @@
+---
+title: Pages
+---

packages/core/dev-test/backends/proxy/_nested_pages/posts/hello-world/index.md

@@ -0,0 +1,5 @@
+---
+title: Hello World
+---
+
+Coffee is a small tree or shrub that grows in the forest understory in its wild form, and traditionally was grown commercially under other trees that provided shade. The forest-like structure of shade coffee farms provides habitat for a great number of migratory and resident species.

packages/core/dev-test/backends/proxy/_nested_pages/posts/index.md

@@ -0,0 +1,3 @@
+---
+title: Posts
+---

packages/core/dev-test/backends/proxy/config.yml

@@ -504,3 +504,22 @@ collections:
         label: Date
         widget: datetime
         i18n: duplicate
+  - name: pages
+    label: Nested Pages
+    label_singular: 'Page'
+    folder: packages/core/dev-test/backends/proxy/_nested_pages
+    create: true
+    # adding a nested object will show the collection folder structure
+    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: { label: 'Path', index_file: 'index' }
+    fields:
+      - label: Title
+        name: title
+        widget: string
+      - label: Body
+        name: body
+        widget: markdown