Examine source code of SteamMarketYearDisplay

{
  "manifest_version": 3,
  "name": "SteamMarketYearDisplay",
  "browser_specific_settings": {
    "gecko": {
      "id": "{99e7edd9-7e7d-4e3c-bb2e-b4f9810d3518}"
    }
  },
  "description": "This extension will display the year of Market transactions",
  "version": "1.1",
  "host_permissions": [
    "https://steamcommunity.com/market/listings/**"
  ],
  "optional_host_permissions": [
    "*://*/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://steamcommunity.com/market/listings/**"
      ],
      "js": [
        "js/SteamMarketListingsInjector.js"
      ],
      "run_at": "document_start"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "js/OverwrittenFunction.js"
      ],
      "matches": [
        "*://*/*"
      ]
    }
  ]
}