Examine source code of GCR Renamer

{
  "name": "GCR Renamer For Firefox",
  "version": "1.0.0",
  "manifest_version": 2,
  "background": {
    "scripts": [
      "./js/background.js"
    ]
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://classroom.google.com/*"
      ],
      "js": [
        "./js/rename.js"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "config.html",
    "default_icon": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "gcr-renamer@thatunknowndude.youtube.com"
    }
  }
}