Examine source code of My Corona

{
  "manifest_version": 2,
  "name": "My Corona",
  "version": "1.0",
  "description": "Replace coronavirus with Corona beer and take the edge off.",
  "icons": {
    "350": "corona-icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "corona-replace.js"
      ]
    }
  ]
}