add-sw01 (#2393)

docs/extensions.md

@@ -243,6 +243,10 @@ Check out [microbit.org](http://microbit.org/resellers/) for more information on
   "name": "Minode Kit",
   "url":"/pkg/minodekit/pxt-minode",
   "cardType": "package"
+}, {
+  "name": "XinaBox SW01 Advanced Weather Sensor",
+  "url":"/pkg/xinabox/pxt-SW01",
+  "cardType": "package"
 }, {
   "name": "Grove inventor kit",
   "url":"/pkg/Seeed-Studio/pxt-grove",