Examine source code of Corona Cyrus

{
  "manifest_version": 2,
  "name": "Corona Cyrus",
  "version": "0.0.3",
  "description": "Replace all mentions of coronavirus with Miley Cyrus",
  "page_action": {
    "default_icon": {
      "16": "images/icon_16x16.png",
      "32": "images/icon_32x32.png",
      "48": "images/icon_48x48.png",
      "128": "images/icon_128x128.png"
    }
  },
  "icons": {
    "16": "images/icon_16x16.png",
    "32": "images/icon_32x32.png",
    "48": "images/icon_48x48.png",
    "128": "images/icon_128x128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "main.js"
      ],
      "run_at": "document_end"
    }
  ]
}