Extension: add Coding For Good Kit (#6680)

Co-authored-by: Galen Nickel <gnickel@aquent.com>

Author: martinwork

docs/extensions/extension-gallery.md

@@ -392,6 +392,10 @@ Many extensions are available to work with interface kits, add-on hardware, or o
 
 ```codecard
 [{
+   "name": "FWD Edu Coding For Good Kit",
+   "url": "/pkg/Forward-Education/pxt-coding-for-good",
+   "cardType": "package"
+}, {
    "name": "Smarthon Smart Home IoT Maker Kit",
    "url": "/pkg/SMARTHON/pxt-smarthome",
    "cardType": "package"

targetconfig.json

@@ -436,6 +436,7 @@
             "siyeenove/pxt_pybit": { "tags": [ "Robotics" ] },
             "nathanpervin/pxt-tm1638": { "tags": [ "Lights and Display" ] },
             "bestmodules-libraries/pxt-bmduino": { "tags": [ "Science" ] },
+            "forward-education/pxt-coding-for-good": { "tags": [ "Science" ] },
             "microsoft/pxt-simx-sample": {
                 "simx": {
                     "sha": "7301f5900879b85127482d79bab48f03c25690a8",