Examine source code of MakeEntGreatAgain

{
  "manifest_version": 2,
  "name": "MakeEntGreatAgain",
  "version": "1.0",
  "description": "Remet la charte de l'ancien ENT.",
  "icons": {
    "48": "icons/border-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://ent.cesi.fr/*"
      ],
      "js": [
        "makeentgreatagain.js"
      ]
    }
  ]
}