add LPS22 (#2387)

docs/extensions.md

@@ -341,6 +341,10 @@ Check out [microbit.org](http://microbit.org/resellers/) for more information on
     "name": "BMP280 Barrometer",
     "url": "/pkg/rebeccaclavier/pxt-bmp280",
     "cardType": "package"
+}, {
+    "name": "LPS22 Pressure",
+    "url": "/pkg/makecode-extensions/LPS22",
+    "cardType": "package"
 }, {
     "name": "LIS2DW12 motion sensor",
     "url": "/pkg/makecode-extensions/LIS2DW12",