Request to persist cookies back into config.conf when gemini-webapi updates it upstream

[dhananjaipai]

Since the gemini-webapi client always rotates the cookies on process start, when the docker container is restarted, the cookies will have to be set manually. Would be great if the file is auto updated (and mounted with volume mount as per #58) so that you can set it and forget, and use restart: unless-stopped in the docker-compose.yml in production

You could also document below steps to get the cookies in README.md

• Go to gemini.google.com and sign in
• Press F12 → Application tab → Cookies
• Copy __Secure-1PSID, __Secure-1PSIDTS