Examine source code of Job Tracker Automator

{
  "manifest_version": 3,
  "name": "Job Tracker Automator",
  "version": "1.0.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "contact@abbos.me",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "description": "Automatically capture job applications and save them to your Job Tracker.",
  "permissions": [
    "storage",
    "activeTab"
  ],
  "host_permissions": [
    "*://*.linkedin.com/jobs/*",
    "*://*.indeed.com/*",
    "*://*.hh.uz/*",
    "http://localhost:3001/*"
  ],
  "action": {
    "default_popup": "index.html"
  },
  "background": {
    "service_worker": "background.js",
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.linkedin.com/jobs/*",
        "*://*.indeed.com/*",
        "*://*.hh.uz/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  }
}