When was this website published?

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "When was this website published?",
  "description": "Find out when the webpage you currently browse was created",
  "version": "1.0.0",
  "browser_action": {
    "default_icon": {
      "19": "images/icon19x19.png",
      "38": "images/icon38x38.png"
    },
    "default_title": "When was this website published",
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "images/icon16x16.png",
    "48": "images/icon48x48.png",
    "128": "images/icon128x128.png"
  },
  "permissions": [
    "http://web.archive.org/",
    "tabs"
  ],
  "manifest_version": 2
}