Examine source code of Feed cleaner

{
  "manifest_version": 2,
  "name": "Feed remover",
  "version": "1.0",
  "description": "Removes feed recommendations from X, pikabu, and linkedin",
  "permissions": [
    "*://*.twitter.com/*",
    "*://*.x.com/*",
    "*://*.pikabu.ru/*",
    "*://*.linkedin.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.twitter.com/*",
        "*://*.x.com/*"
      ],
      "js": [
        "twitter.js"
      ]
    },
    {
      "matches": [
        "*://*.pikabu.ru/*"
      ],
      "css": [
        "pikabu.css"
      ]
    },
    {
      "matches": [
        "*://*.linkedin.com/*"
      ],
      "css": [
        "linkedin.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{269840ad-f159-412d-a925-ce146f48eeaf}"
    }
  }
}