Examine source code of Vimer

{
  "manifest_version": 2,
  "name": "Vimer",
  "version": "1.0",
  "description": "Navigate web pages using Vim shortcuts.",
  "permissions": [
    "activeTab"
  ],
  "icons": {
    "64": "icons/icon64.png",
    "128": "icons/icon128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_action": {
    "default_title": "Vimer",
    "default_icon": "icons/icon64.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6ca13fb4-f34b-4d28-8f79-730a9a5018ec}",
      "strict_min_version": "114.0"
    }
  }
}