Examine source code of ReleaseMarkdown

{
  "manifest_version": 2,
  "name": "ReleaseMarkdown",
  "version": "1.0",
  "permissions": [
    "activeTab",
    "<all_urls>"
  ],
  "icons": {
    "48": "icons/border-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "to_markdown.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{aa0629b3-1901-43f3-b194-da43122a362c}"
    }
  }
}