Examine source code of Visiooff

{
  "description": "Hide HS Visio content in hs.fi",
  "manifest_version": 2,
  "name": "Visiooff",
  "version": "1.0",
  "homepage_url": "https://github.com/miikaah/visiooff",
  "icons": {
    "48": "icon48x48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://*.hs.fi/*"
      ],
      "js": [
        "visiooff.js"
      ]
    }
  ]
}