Add Nicla to resulting json

Author: facchinm

extras/package_index.json.NewTag.template

@@ -40,6 +40,9 @@
             },
             {
               "name": "Raspberry Pi Pico"
+            },
+            {
+              "name": "Nicla Sense ME"
             }
           ],
           "toolsDependencies": [
@@ -245,6 +248,51 @@
               "name": "rp2040tools"
             }
           ]
+        },
+        {
+          "name": "Arduino Mbed OS Nicla Boards",
+          "architecture": "mbed_nicla",
+          "version": "%%VERSION%%",
+          "category": "Arduino",
+          "url": "http://downloads.arduino.cc/cores/staging/%%NICLA_FILENAME%%",
+          "archiveFileName": "%%NICLA_FILENAME%%",
+          "checksum": "SHA-256:%%NICLA_CHECKSUM%%",
+          "size": "%%NICLA_SIZE%%",
+          "help": {
+            "online": "https://github.com/arduino/ArduinoCore-mbed/issues"
+          },
+          "boards": [
+            {
+              "name": "Nicla Sense ME"
+            }
+          ],
+          "toolsDependencies": [
+            {
+              "packager": "arduino",
+              "name": "openocd",
+              "version": "0.11.0-arduino2"
+            },
+            {
+              "packager": "arduino",
+              "name": "arm-none-eabi-gcc",
+              "version": "7-2017q4"
+            },
+            {
+              "packager": "arduino",
+              "name": "bossac",
+              "version": "1.9.1-arduino2"
+            },
+            {
+              "packager": "arduino",
+              "version": "0.10.0-arduino1",
+              "name": "dfu-util"
+            },
+            {
+              "packager": "arduino",
+              "version": "1.0.2",
+              "name": "rp2040tools"
+            }
+          ]
         }
       ],
       "tools": []