Examine source code of Google Calendar Compact

{
  "manifest_version": 2,
  "name": "Google Calendar Compact - F5 Sites",
  "version": "1.0",
  "description": "Compact Google Calendar to view better the events, hidding the header. By F5 Sites (www.f5ites.com)",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "storage",
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "fmatelli@gmail.com",
      "strict_min_version": "58.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://calendar.google.com/*"
      ],
      "css": [
        "style.css"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": {
      "48": "icons/icon-48.png"
    },
    "default_title": "Toggle Compact Calendar",
    "default_popup": "popup.html"
  }
}