Examine source code of WordVault

{
  "manifest_version": 3,
  "name": "WordVault",
  "version": "1.4.2",
  "description": "Extension to save dictionary lookups",
  "permissions": [
    "activeTab",
    "downloads",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "sebastian.axell98@gmail.com",
      "strict_min_version": "57.0"
    },
    "gecko_android": {
      "strict_min_version": "42.0"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "scripts/content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "action": {
    "default_icon": "images/logo.png"
  }
}