Examine source code of Rhymey

{
  "name": "Rhymey",
  "short_name": "Rhymey",
  "description": "Get rhymes for double-clicked words, even in Google Docs!",
  "version": "4.0.1",
  "manifest_version": 3,
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*",
        "http://localhost/*"
      ],
      "js": [
        "content_scripts/content-0.js"
      ],
      "css": [
        "content_scripts/content-0.css"
      ],
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "permissions": [
    "storage"
  ],
  "options_page": "options_ui/page.html",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "rhymey@rhymey.com"
    }
  }
}