Examine source code of U21P Score Beta

{
  "manifest_version": 2,
  "name": "U21P Score Beta",
  "version": "0.6.0",
  "description": "Displays USA Target Skills Scores and AMTS values on HattrickPortal Tracker pages. User must have access to player skills.",
  "icons": {
    "16": "U21P16.png",
    "48": "U21P48.png",
    "128": "U21P128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.hattrickportal.pro/Player.aspx*",
        "*://*.hattrickportal.pro/Tracker/Player.aspx*"
      ],
      "js": [
        "playerview.js"
      ]
    },
    {
      "matches": [
        "*://*.hattrickportal.pro/Tracker/*/Lists.aspx?ListID=*"
      ],
      "js": [
        "listview.js"
      ]
    },
    {
      "matches": [
        "*://*.hattrickportal.pro/Tracker/*/Players.aspx*"
      ],
      "js": [
        "searchview.js"
      ]
    }
  ]
}