Examine source code of Single key shortcuts

{
  "manifest_version": 2,
  "name": "Single key shortcuts",
  "version": "1.0.2resigned1",
  "description": "Adds single key shortcuts for tab switching",
  "icons": {
    "32": "icons/enabled.svg"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "main.js"
      ],
      "match_about_blank": true,
      "run_at": "document_start"
    }
  ],
  "permissions": [
    "tabs"
  ],
  "browser_action": {
    "default_icon": "icons/enabled.svg",
    "default_title": "Toggle Single key shortcuts"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{35f2859c-58e6-4e1a-8272-2e4bfe2d562e}"
    }
  }
}