Examine source code of Macro Commander

{
  "manifest_version": 2,
  "version": "2.1.0",
  "name": "Macro Commander Web Plugin for Firefox",
  "description": "Automate web pages and applications using Macro Commander.",
  "page_action": {
    "default_popup": "index.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "match_about_blank": true,
      "js": [
        "content_scr1.js"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ],
  "permissions": [
    "activeTab",
    "tabs",
    "webNavigation",
    "scripting"
  ],
  "icons": {
    "64": "mc_icon64x64.png",
    "128": "mc_icon128x128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{f25c83e0-e650-4018-a1d0-79a57ce3f213}",
      "strict_min_version": "148.0"
    }
  }
}