Examine source code of ZedMode

{
  "manifest_version": 3,
  "name": "ZedMode",
  "version": "1.2.1",
  "description": "Enable dark mode for tryhackme.com",
  "permissions": [
    "activeTab",
    "storage",
    "tabs",
    "webNavigation",
    "webRequest",
    "unlimitedStorage"
  ],
  "action": {
    "default_icon": {
      "16": "images/icon16.png",
      "48": "images/icon48.png",
      "128": "images/icon128.png"
    },
    "default_title": "Toggle Zed Mode"
  },
  "icons": {
    "16": "images/icon16.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.tryhackme.com/*",
        "https://tryhackme.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "web_accessible_resources": [
    {
      "resources": [
        "styles.css",
        "injectScript.js"
      ],
      "matches": [
        "https://www.tryhackme.com/*",
        "https://tryhackme.com/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "zedmode@renegade.zed"
    }
  }
}