Add Nordic nRF52833

Author: xudongzheng

utils/uf2families.json

@@ -94,6 +94,11 @@
         "short_name": "STM32F1",
         "description": "ST STM32F103"
     },
+    {
+        "id": "0x621e937a",
+        "short_name": "NRF52833",
+        "description": "Nordic NRF52833"
+    },
     {
         "id": "0x647824b6",
         "short_name": "STM32F0",
@@ -169,4 +174,4 @@
         "short_name": "STM32L4",
         "description": "ST STM32L4xx"
     }
-]
+]