Examine source code of Tempo — Video Speed Control

{
  "manifest_version": 3,
  "name": "Tempo — Video Speed Control",
  "version": "1.0.0",
  "description": "Change YouTube playback speed quickly and remember it locally.",
  "author": "Colin Knapp",
  "icons": {
    "16": "icons/tempo.svg",
    "32": "icons/tempo.svg",
    "48": "icons/tempo.svg",
    "96": "icons/tempo.svg"
  },
  "action": {
    "default_icon": "icons/tempo.svg",
    "default_title": "Tempo — Video Speed Control",
    "default_popup": "popup/popup.html"
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*",
        "https://m.youtube.com/*"
      ],
      "js": [
        "src/core.js",
        "src/content.js"
      ],
      "css": [
        "src/indicator.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "tempo@extensions.colinknapp.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}