Examine source code of YT Dimmer

{
  "manifest_version": 2,
  "name": "YT Dimmer",
  "description": "Softens sudden flashes and bright video scenes for more comfortable viewing.",
  "version": "2.1.0",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "permissions": [
    "storage",
    "activeTab"
  ],
  "commands": {
    "toggle-protection": {
      "suggested_key": {
        "default": "Alt+Shift+D",
        "mac": "Alt+Shift+D"
      },
      "description": "Toggle YT Dimmer protection"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "yt-dimmer@c-w-d-harshit.github.io",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "YT Dimmer",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}