Examine source code of Markdown Viewer Plus

{
  "manifest_version": 2,
  "name": "Markdown Viewer",
  "version": "1.0",
  "description": "Preview Markdown files directly in the browser with additional useful features.",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "<all_urls>"
  ],
  "browser_action": {
    "default_icon": "icons/icon-48.png",
    "default_title": "Markdown Viewer",
    "default_popup": "popup/popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_scripts/content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0f50a2fc-a6ae-47a6-829e-bd63a1b8a1fb}"
    }
  }
}