feat: folder creation (#696)

packages/demo/public/config.yml

@@ -2,6 +2,7 @@ backend:
   name: test-repo
 site_url: 'https://staticcms.org/'
 media_folder: assets/uploads
+media_library_folder_support: true
 locale: en
 i18n:
   # Required and can be one of multiple_folders, multiple_files or single_file

packages/demo/public/index.html

@@ -17,19 +17,17 @@
             "lobby.jpg": {
               content: "",
             },
-          },
-        },
-        _posts: {
-          assets: {
-            uploads: {
-              "moby-dick.jpg": {
-                content: "",
+            'Other Pics': {
+              'moby-dick.jpg': {
+                content: '',
               },
-              "lobby.jpg": {
-                content: "",
+              'lobby.jpg': {
+                content: '',
               },
             },
           },
+        },
+        _posts: {
           "2015-02-14-this-is-a-post.md": {
             content:
               "---\ntitle: This is a YAML front matter post\nimage: /assets/uploads/moby-dick.jpg\ndate: 2015-02-14T00:00:00.000Z\n---\n\n# I Am a Title in Markdown\n\nHello, world\n\n* One Thing\n* Another Thing\n* A Third Thing\n",