Examine source code of Gmail URL Paste

{
  "manifest_version": 2,
  "name": "Gmail URL Paste",
  "description": "Automatically convert selected text to hyperlinks when pasting URLs in Gmail and Google Calendar. This extension is open source and collects no data. Source code: https://github.com/wirtzdan/gmail-url-paste",
  "version": "0.1.0",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "@gmail-url-paste",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://calendar.google.com/*",
        "*://mail.google.com/*"
      ],
      "all_frames": true,
      "run_at": "document_idle",
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}