Examine source code of Rainbow Text

{
  "manifest_version": 2,
  "name": "Rainbow Text",
  "version": "1.0.0",
  "description": "Apply beautiful rainbow colour gradients to text on any webpage. Choose from 6 presets: Neon, Soft Rainbow, Pastel, Ocean, Sunset, and Forest.",
  "author": "Adam",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_action": {
    "default_icon": "icons/rainbow-48.svg",
    "default_title": "Rainbow Text",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "auto-apply.js"
      ],
      "run_at": "document_end"
    }
  ],
  "icons": {
    "48": "icons/rainbow-48.svg",
    "96": "icons/rainbow-96.svg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "rainbow-text@adamardis.hotmail.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}