Examine source code of Keysmith

{
  "name": "Keysmith",
  "version": "1.2.2",
  "description": "Keysmith is a Mac App and Chrome extension pair that lets you create custom keyboard shortcuts for any app or website.",
  "manifest_version": 2,
  "permissions": [
    "nativeMessaging",
    "tabs",
    "webNavigation",
    "downloads"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "./content.js"
      ],
      "css": [
        "./content.css"
      ],
      "run_at": "document_start"
    }
  ],
  "background": {
    "scripts": [
      "./background.js"
    ],
    "persistent": true
  },
  "icons": {
    "16": "icons/AppIconLight-16.png",
    "32": "icons/AppIconLight-32.png",
    "48": "icons/AppIcon-48.png",
    "128": "icons/AppIcon-128.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/AppIconLight-16.png",
      "32": "icons/AppIconLight-32.png",
      "48": "icons/AppIcon-48.png",
      "128": "icons/AppIcon-128.png"
    },
    "default_title": "Keysmith browser extension"
  },
  "web_accessible_resources": [
    "images/*.png"
  ],
  "default_locale": "en"
}