Examine source code of Dashboard-plugin

{
  "manifest_version": 2,
  "name": "Dashboard",
  "version": "1.0",
  "description": "Quick dashboard utilities for browser",
  "incognito": "spanning",
  "icons": {
    "16": "img/icon.png",
    "128": "img/icon.png"
  },
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'",
  "background": {
    "scripts": [
      "handler.js"
    ]
  },
  "permissions": [
    "tabs",
    "storage",
    "unlimitedStorage",
    "<all_urls>",
    "downloads",
    "clipboardRead",
    "webRequest"
  ],
  "browser_action": {
    "default_icon": {
      "19": "img/icon.png",
      "38": "img/icon.png"
    },
    "default_title": "Dashboard"
  },
  "applications": {
    "gecko": {
      "id": "christian.a.herlein@gmail.com"
    }
  }
}