Add blank page with JSON

Author: IDzyre

_docs/instructor/assignment_preparation/upload_gradeable.md

@@ -0,0 +1,13 @@
+---
+category: Instructor > Assignment Preparation
+title: Upload Gradeable
+redirect_from:
+  - /instructor/upload_gradeable
+---
+
+```json
+{
+    "test": "test"
+}
+
+```