Examine source code of DOM Cleaner

{
  "manifest_version": 3,
  "name": "DOM Cleaner",
  "version": "0.1.2",
  "description": "Remove unwanted web elements by selector.",
  "browser_specific_settings": {
    "gecko": {
      "id": "@dom-cleaner",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_title": "DOM Cleaner"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "src/content.js"
      ],
      "run_at": "document_start"
    }
  ]
}