Examine source code of IMDb/RT 2 Wikifeet

{
  "manifest_version": 2,
  "name": "IMDb/RT 2 Wikifeet",
  "version": "1.0",
  "description": "Adds a browser action icon to the toolbar. When visiting IMDb or Rotten Tomatoes website actress page, jumps to wikifeet page of the actress",
  "homepage_url": "https://tnani.com",
  "icons": {
    "48": "icons/wikifeet-48.png"
  },
  "permissions": [
    "tabs",
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/wikifeet-19.png",
    "default_title": "IMDb/RT 2 Wikifeet",
    "default_popup": "popup/popup.html"
  }
}