Examine source code of PollBlock - LinkedIn

{
  "manifest_version": 2,
  "name": "__MSG_app_name__",
  "version": "0.1.1",
  "description": "__MSG_app_description__",
  "default_locale": "pt_BR",
  "content_scripts": [
    {
      "matches": [
        "https://*.linkedin.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "512": "assets/icon_stop@512.png"
  }
}