Examine source code of History Cleaner

{
  "manifest_version": 2,
  "name": "History Cleaner",
  "version": "1.0",
  "description": "Remove all negative websites from history",
  "permissions": [
    "history"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "matvej5554444333@gmail.com",
      "strict_min_version": "78.0"
    }
  }
}