Examine source code of ReadMode

{
  "name": "ReadMode",
  "version": "1.0",
  "description": "View page pure text.",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "阅读模式"
  },
  "icons": {
    "128": "icon.png"
  },
  "options_ui": {
    "page": "options.htm"
  },
  "permissions": [
    "<all_urls>"
  ],
  "manifest_version": 2
}