Examine source code of Feed Media Tamer

{
  "manifest_version": 2,
  "name": "Feed Media Tamer (X/FB/IG/Linkedin)",
  "description": "Hides videos until clicked, grayscales feed, supports X, Linkedin, Facebook & Instagram.",
  "version": "1.2.0",
  "permissions": [
    "storage",
    "tabs",
    "*://twitter.com/*",
    "*://*.twitter.com/*",
    "*://x.com/*",
    "*://*.x.com/*",
    "*://facebook.com/*",
    "*://*.facebook.com/*",
    "*://instagram.com/*",
    "*://*.instagram.com/*",
    "*://linkedin.com/*",
    "*://*.linkedin.com/*"
  ],
  "browser_action": {
    "default_title": "Media Tamer",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://twitter.com/*",
        "*://*.twitter.com/*",
        "*://x.com/*",
        "*://*.x.com/*",
        "*://facebook.com/*",
        "*://*.facebook.com/*",
        "*://instagram.com/*",
        "*://*.instagram.com/*",
        "*://linkedin.com/*",
        "*://*.linkedin.com/*"
      ],
      "js": [
        "content-script.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{7e7e81fa-b4d1-44b8-aa75-d336fb0be50c}"
    }
  }
}