doc: Hosting on railway.app

[ririko5834]

Is your feature request related to a problem? Please describe. I don't know how to host this on railway.app

Describe the solution you'd like Write guide how to host chatwoot on service https://railway.app railway supports database plugins, so both database and chatwoot can be hosted on one plane

Describe alternatives you've considered Write a guide for https://fly.io or https://replit.com

Additional context Add any other context or screenshots about the feature request here.

[sojan-official]

ref : https://github.com/chatwoot/chatwoot/discussions/3076

[pranavrajs]

Moving this issue to the docs repository.

[ptahdunbar]

props brody192 for a working example.