Examine source code of scratchdécorer

{
  "manifest_version": 2,
  "name": "scratchdécorer",
  "version": "1.0",
  "description": "Ajoute une bordure orange et bleue à scratch.mit.edu",
  "icons": {
    "48": "icon/border-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.scratch.mit.edu/*"
      ],
      "js": [
        "borderify.js"
      ]
    }
  ]
}