Update docs.json

Delete whole section from .json to try to fix engine.

Author: Amanda Butler

docs.json

@@ -133,15 +133,6 @@
               {"type": "markdown", "url": "https://github.com/ARMmbed/Handbook/blob/new_engine/docs/reference/api/connectivity/networksocket/SocketAddress.md"}
             ]
           },
-          {
-            "title": "Bluetooth",
-            "intro": {"type": "markdown", "url": "https://github.com/ARMmbed/Handbook/blob/new_engine/docs/reference/api/connectivity/bluetooth/bluetooth.md"},
-            "sources": [
-                {"type": "markdown", "url": "https://github.com/ARMmbed/Handbook/blob/new_engine/docs/reference/api/connectivity/bluetooth/BLE.md"},
-                {"type": "markdown", "url": "https://github.com/ARMmbed/Handbook/blob/new_engine/docs/reference/api/connectivity/bluetooth/HeartRateService.md"},
-                {"type": "markdown", "url": "https://github.com/ARMmbed/Handbook/blob/new_engine/docs/reference/api/connectivity/bluetooth/iBeacon.md"}
-            ]
-          },
           {
             "title": "Security",
             "intro": {"type": "markdown", "url": "https://github.com/ARMmbed/Handbook/blob/new_engine/docs/reference/api/security/security.md"},