Examine source code of Quick Marker

{
  "manifest_version": 2,
  "name": "Quick Marker",
  "version": "1.0.0",
  "description": "Highlight text on the current page with one click and remember your highlights per-site.",
  "applications": {
    "gecko": {
      "id": "{d9b49c51-38b7-4b8b-9d8b-9d6a3a1ca7c2}",
      "strict_min_version": "109.0"
    }
  },
  "icons": {
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Quick Marker",
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true,
    "browser_style": true
  }
}