Examine source code of OnPageSeoCheck

{
  "manifest_version": 2,
  "name": "OnPageSeoCheck",
  "version": "1.1",
  "description": "Checks websites for common onpage seo errors.",
  "icons": {
    "16": "icons/onpageseocheck-16.png",
    "32": "icons/onpageseocheck-32.png",
    "48": "icons/onpageseocheck-48.png",
    "96": "icons/onpageseocheck-96.png",
    "128": "icons/onpageseocheck-128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content-script.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background-script.js"
    ],
    "persistent": false,
    "service_worker": false
  },
  "browser_action": {
    "default_icon": "icons/onpageseocheck-32.png",
    "theme_icons": [
      {
        "light": "icons/onpageseocheck-32.png",
        "dark": "icons/onpageseocheck-32.png",
        "size": 32
      }
    ],
    "default_title": "OnPageSeoCheck"
  },
  "sidebar_action": {
    "browser_style": true,
    "default_title": "OnPageSeoCheck",
    "default_panel": "sidebar/sidebar.html",
    "default_icon": "icons/onpageseocheck-48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9c3f49f3-9346-40d5-ba97-0b1872526a41}"
    }
  }
}