Examine source code of ShortBlock

{
  "manifest_version": 2,
  "name": "ShortBlock",
  "version": "1.0",
  "description": "Block shorts.",
  "icons": {
    "48": "icons/shortblock.jpg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "shortblock@local",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "webRequest",
    "storage",
    "webRequestBlocking",
    "*://*.youtube.com/*"
  ],
  "data_collection_permissions": {
    "required": [],
    "optional": []
  },
  "browser_action": {
    "default_popup": "pop2.html",
    "default_title": "ShortBlock - Short-form Content Manager"
  },
  "background": {
    "scripts": [
      "bg.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "yt.js"
      ],
      "run_at": "document_start"
    }
  ]
}