Examine source code of Elden Email

{
  "manifest_version": 2,
  "name": "Elden Email",
  "version": "1.1.2",
  "description": "Shows an Elden Ring banner when you send an email",
  "permissions": [
    "storage",
    "activeTab",
    "scripting"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "assets/icon.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*",
        "https://outlook.office.com/*",
        "https://outlook.live.com/*",
        "https://outlook.office365.com/*",
        "https://mail.proton.me/*",
        "https://mail.aol.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "style.css"
      ],
      "all_frames": true
    }
  ],
  "icons": {
    "48": "assets/icon.png"
  },
  "web_accessible_resources": [
    "assets/email_sent_yellow.png",
    "assets/email_sent_blue.png",
    "assets/email_sent_red.png",
    "assets/elden_ring_sound.mp3",
    "assets/Matinia.otf"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{e7b84430-dae5-41e6-bb6f-9d01b02c4347}"
    }
  }
}