Examine source code of outline.com_addon

{
  "description": "Opens the current tab in outline.com",
  "manifest_version": 2,
  "name": "outline",
  "version": "1.0",
  "author": "Jamal A. Mohamed",
  "background": {
    "scripts": [
      "outline.js"
    ]
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": {
      "48": "icons/outline-48.png",
      "96": "icons/outline-96.png"
    }
  }
}