Examine source code of Hide Zhihu Topbar

{
  "description": "A simple extention to hide the topbar of Zhihu site.",
  "manifest_version": 2,
  "name": "Hide Zhihu Topbar",
  "version": "1.2",
  "icons": {
    "32": "icons/hide-32.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.zhihu.com/*"
      ],
      "js": [
        "hide-zhihu-topbar.js"
      ]
    }
  ]
}