Examine source code of Coffre Crypto

{
  "manifest_version": 2,
  "name": "Coffre Crypto",
  "version": "1.0.0",
  "description": "Chiffrez et déchiffrez localement de courts messages avec une clé publique RSA + Support whatsapp chiffrement et dechiffrement à la volée",
  "icons": {
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png"
  },
  "permissions": [
    "storage",
    "clipboardWrite",
    "https://web.whatsapp.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_icon": {
      "32": "icons/icon-32.png"
    },
    "default_title": "Coffre Crypto",
    "default_popup": "popup/popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://web.whatsapp.com/*"
      ],
      "js": [
        "whatsapp-content.js"
      ],
      "css": [
        "whatsapp-content.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "coffre-crypto@sadek-it.fr",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}