Examine source code of DocsKeys

{
  "manifest_version": 3,
  "name": "DocsKeys",
  "description": "Vim-style keyboard shortcuts for Google Docs",
  "version": "1.3.3",
  "icons": {
    "32": "icons/32.png",
    "128": "icons/128.png"
  },
  "action": {
    "default_popup": "index.html",
    "default_icon": "icons/32.png"
  },
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "https://docs.google.com/*"
      ]
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "page_script.js"
      ],
      "matches": [
        "https://docs.google.com/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "dockeys@tirthd16"
    }
  }
}