Examine source code of Markdown file reader

{
  "manifest_version": 2,
  "name": "Markdown file reader",
  "version": "0.1",
  "description": "View markdown files in Firefox.",
  "icons": {
    "16": "icons/016px.png",
    "24": "icons/024px.png",
    "32": "icons/032px.png",
    "48": "icons/048px.png",
    "64": "icons/064px.png",
    "96": "icons/096px.png",
    "128": "icons/128px.png"
  },
  "permissions": [
    "storage"
  ],
  "background": {
    "page": "background/page.html"
  },
  "options_ui": {
    "page": "options/page.html",
    "browser_style": true
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*.md",
        "*://*/*.markdown",
        "file:///*.md",
        "file:///*.markdown"
      ],
      "js": [
        "libraries/marked/marked.min.js",
        "libraries/dompurify/purify.min.js",
        "content_scripts/reformat-page.js"
      ],
      "run_at": "document_start"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{dc725d36-141b-47c9-ae1f-0a6913f1cc80}"
    }
  }
}