Approve Seeed Studio as approved organisation (#614)

* Add Grove inventor kit package to list

* Approve Seeed Studio organisation

The foundation are working closely with Seeed who have assured that packages meet requirements

docs/packages.md

@@ -84,6 +84,10 @@
   "url":"/pkg/mbitfun/pxt-katakana",
   "cardType": "package"
   }, {
+  "name": "Grove inventor kit",
+  "url":"/pkg/Seeed-Studio/pxt-grove",
+  "cardType": "package"
+  }, {
   "name": "PCA9685 LED controller",
   "url":"/pkg/jdarling/pxt-pca9685",
   "cardType": "package"