Examine source code of vimmy

{
  "manifest_version": 2,
  "name": "vimmy",
  "version": "1.1",
  "description": "vim navigation",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{4ab61dd9-6976-49ba-95bf-f2b41eeb4d3c}"
    }
  }
}