Examine source code of YouTube Blocker

{
  "manifest_version": 2,
  "name": "YouTube Blocker",
  "description": "Block unwanted YouTube channels.",
  "version": "1.0.0",
  "browser_action": {
    "default_title": "YouTube Blocker",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "./icons/icon-16.png",
      "48": "./icons/icon-48.png",
      "128": "./icons/icon-128.png"
    }
  },
  "icons": {
    "16": "./icons/icon-16.png",
    "48": "./icons/icon-48.png",
    "128": "./icons/icon-128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "js/content.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html",
    "browser_style": true,
    "chrome_style": true
  },
  "permissions": [
    "storage"
  ]
}