Examine source code of Two Columns Wikipedia

{
  "description": "Shows wikipedia pages in two columns",
  "manifest_version": 2,
  "name": "Two Columns Wikipedia",
  "version": "1.0",
  "homepage_url": "https://github.com/arturolinares/two-cols-wikipedia",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "page_action": {
    "default_icon": "icons/off.svg",
    "browser_style": true
  },
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{57752ba4-366a-4d02-b0dc-08189de585a9}"
    }
  }
}