Examine source code of Scoreless

{
  "manifest_version": 2,
  "name": "Scoreless",
  "version": "0.8.0",
  "description": "Hides thumbnails and trims titles on YouTube so match highlights don't give away the score.",
  "author": "Anne Albert",
  "browser_specific_settings": {
    "gecko": {
      "id": "scoreless@annealbert.dev",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "storage",
    "https://*.youtube.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://*.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_start",
      "all_frames": false
    }
  ],
  "browser_action": {
    "default_title": "Scoreless",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon-16.png",
      "32": "icon-32.png",
      "48": "icon-48.png"
    }
  },
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png",
    "48": "icon-48.png",
    "96": "icon-96.png",
    "128": "icon-128.png"
  }
}