Examine source code of Save HTML as Markdown

{
  "manifest_version": 2,
  "name": "Save HTML as Markdown",
  "description": "A browser extension to save HTML pages to markdown.",
  "version": "0.1.0",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "permissions": [
    "activeTab",
    "downloads"
  ],
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{32bf0bd4-a369-49a9-ab9f-186197471f1b}"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Default Popup Title",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}