Examine source code of zoom auto close

{
  "manifest_version": 2,
  "name": "zoom auto close",
  "description": "This extension automatically closes tabs left by zoom meeting application.",
  "version": "1.0",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://zoom.us/postattendee",
        "https://*.zoom.us/postattendee*",
        "https://zoom.us/j/*",
        "https://*.zoom.us/j/*",
        "https://zoom.us/s/*",
        "https://*.zoom.us/s/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ]
}