Examine source code of Lighter

{
  "description": "Adds a button to open current page with Google Web Light",
  "manifest_version": 2,
  "name": "Lighter",
  "version": "1.2resigned1",
  "homepage_url": "https://github.com/harshit-j/Lighter",
  "icons": {
    "256": "icon256.png"
  },
  "permissions": [
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icon256.png"
  },
  "commands": {
    "light": {
      "suggested_key": {
        "default": "Alt+Z"
      },
      "description": "Open with Google Web Light"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1410a77c-c320-4720-a2e5-157f178e3770}"
    }
  }
}