Examine source code of subline

{
  "name": "subline",
  "version": "0.0.3",
  "description": "improve the news",
  "permissions": [
    "activeTab",
    "storage",
    "https://subline.app/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": {
      "16": "images/favicon-16.png",
      "48": "images/favicon-48.png",
      "128": "images/favicon-128.png"
    },
    "default_title": "subline | improve the news",
    "default_popup": "index.html"
  },
  "icons": {
    "16": "images/favicon-16.png",
    "48": "images/favicon-48.png",
    "128": "images/favicon-128.png"
  },
  "manifest_version": 2
}