Examine source code of Nektion Jira link

{
  "name": "Nektion Links",
  "version": "1.3",
  "browser_specific_settings": {
    "gecko": {
      "id": "jeff@nektion.com"
    }
  },
  "description": "Navigate to the Nektion page that matches your current page. (Jira linked items)",
  "permissions": [
    "activeTab",
    "tabs",
    "declarativeContent",
    "storage",
    "https://*.nektion.com/*",
    "http://localhost:8080/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "page_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "images/get_started16.png",
      "32": "images/get_started32.png",
      "48": "images/get_started48.png",
      "128": "images/get_started128.png"
    }
  },
  "icons": {
    "16": "images/get_started16.png",
    "32": "images/get_started32.png",
    "48": "images/get_started48.png",
    "128": "images/get_started128.png"
  },
  "manifest_version": 2
}