You are a Python developer. Write a script that performs a Google search for a given query and extracts the top results (title, URL, description). Use requests and BeautifulSoup. The script must: 1) Accept query as argument, 2) Handle pagination (next pages), 3) Respect robots.txt and use polite delays, 4) Rotate user agents, 5) Save results to CSV, 6) Handle CAPTCHAs (detect and alert), 7) Provide option to use proxies. Add comments and a README.