Examine source code of Feedly Auto Refresh

{
  "manifest_version": 3,
  "name": "Feedly Auto Refresh",
  "version": "1.0.1",
  "description": "Automatically refreshes Feedly and displays unread counts on tab icon",
  "permissions": [
    "storage",
    "alarms",
    "scripting"
  ],
  "host_permissions": [
    "*://feedly.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://feedly.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "icons": {
    "16": "icons/16.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "feedly-auto-refresh@manse.jp"
    }
  }
}