manifest.json

{
  "manifest_version": 2,
  "name": "Yet another XKCD substitutions chome extension",
  "description": "Making everyday browsing a bit more fun",
  "version": "1.0",
  "browser_action": {
    "default_icon": "/img/icon.png",
    "default_title": "XKCD Substitutions"
  },
  "background": {
    "scripts": ["/js/background.js"]
  },
  "content_scripts": [
    {
      "matches": ["<all_urls>"],
      "run_at": "document_idle",
      "js": ["/js/substitutions.js"]
    }
  ],
  "permissions": [
    "activeTab",
    "storage",
    "background"
  ]
}