Of course I got the levels wrong

Author: iriark01

docs.json

@@ -778,22 +778,22 @@
                                 "url": "https://github.com/ARMmbed/mbed-os-5-docs/blob/development/docs/reference/runtime/static_memory_optimization.md"
                             }
                         ]
+                    }
+                ]
+            },
+            {
+                "title": "Mbed OS fundamentals",
+                "sources": [{
+                        "type": "markdown",
+                        "url": "https://github.com/ARMmbed/mbed-os-5-docs/blob/development/docs/reference/runtime/Execution.md"
                     },
                     {
-                        "title": "Mbed OS fundamentals",
-                        "sources": [{
-                                "type": "markdown",
-                                "url": "https://github.com/ARMmbed/mbed-os-5-docs/blob/development/docs/reference/runtime/Execution.md"
-                            },
-                            {
-                                "type": "markdown",
-                                "url": "https://github.com/ARMmbed/mbed-os-5-docs/blob/development/docs/reference/runtime/Bootstrap.md"
-                            },
-                            {
-                                "type": "markdown",
-                                "url": "https://github.com/ARMmbed/mbed-os-5-docs/blob/development/docs/api/thread_safety.md"
-                            }
-                        ]
+                        "type": "markdown",
+                        "url": "https://github.com/ARMmbed/mbed-os-5-docs/blob/development/docs/reference/runtime/Bootstrap.md"
+                    },
+                    {
+                        "type": "markdown",
+                        "url": "https://github.com/ARMmbed/mbed-os-5-docs/blob/development/docs/api/thread_safety.md"
                     }
                 ]
             },