Examine source code of YouTrack Wider

{
  "description": "Make the YouTrack wider",
  "manifest_version": 2,
  "name": "YouTrack Wider",
  "version": "2.2",
  "homepage_url": "https://github.com/cernyjan/YouTrack-Wider",
  "icons": {
    "48": "icons/ruler-48.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/ruler-48.png",
      "32": "icons/ruler-48.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://youtrack/*",
        "https://youtrack.quadient.group/*",
        "*://*/youtrack*"
      ],
      "js": [
        "jquery-3.2.1.min.js",
        "YouTrack-Wider.js"
      ]
    }
  ]
}