Examine source code of cf-br

{
  "manifest_version": 2,
  "name": "cf-br",
  "version": "1.0",
  "description": "Permite ver o standings do Brasil em um contest no codeforces.",
  "icons": {
    "48": "icons/cf-br48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://codeforces.com/contest/*/standings"
      ],
      "js": [
        "cf-br.js"
      ]
    }
  ]
}