add npm run to extension build commands

Signed-off-by: Sebastian Malton <sebastian@malton.name>

extensions/support-page/package.json

@@ -5,7 +5,7 @@
   "main": "dist/main.js",
   "renderer": "dist/renderer.js",
   "scripts": {
-    "build": "webpack -p",
+    "build": "npm run webpack -p",
     "dev": "webpack --watch",
     "test": "jest --passWithNoTests --env=jsdom src $@"
   },