Examine source code of Text Inserter for Gemini

{
  "manifest_version": 3,
  "name": "Text Inserter for Gemini",
  "version": "1.0.1",
  "description": "Attach long text directly as text files to Gemini prompts.",
  "browser_specific_settings": {
    "gecko": {
      "id": "gemini-text-inserter@local",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "clipboardRead"
  ],
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://gemini.google.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "style.css"
      ],
      "run_at": "document_idle"
    }
  ]
}