Examine source code of Overratd

{
  "name": "Overratd",
  "author": "Garret Lowe",
  "description": "An Extension for Letterboxd which adds rating histograms to public lists based on the author's rating",
  "version": "1.3",
  "manifest_version": 3,
  "permissions": [],
  "content_scripts": [
    {
      "matches": [
        "https://letterboxd.com/*/list/*/"
      ],
      "js": [
        "background.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f517ab73-9ad9-4f3c-9fcc-3c6df6a7a298}",
      "strict_min_version": "58.0"
    }
  },
  "icons": {
    "16": "/images/overratd16.png",
    "32": "/images/overratd32.png",
    "48": "/images/overratd48.png",
    "128": "/images/overratd128.png"
  }
}