Update definition.json for Metro ESP32-S2

Author: tyeth

boards/metroesp32s2/definition.json

@@ -8,7 +8,19 @@
     "productURL":"https://www.adafruit.com/product/4775",
     "documentationURL":"https://learn.adafruit.com/adafruit-metro-esp32-s2",
     "bootloaderBoardName": "adafruit_metro_esp32s2",
-    "installMethod": "uf2",
+    "installMethod": "web-native-usb",
+    "esptool": {
+      "fileSystemSize": 983040,
+      "blockSize": 4096,
+      "offset": "0x310000",
+      "chip": "esp32s2",
+      "flashMode": "dio",
+      "flashFreq": "80m",
+      "flashSize": "4MB",
+      "structure": {
+        "0x0": "wippersnapper.metroesp32s2.fatfs.VERSION.combined.bin"
+      }
+    },
     "components":{
        "digitalPins":[
           {