docs: Create self-hosting / install documentation

[tompscanlan]

Summary

OpenMeet has no self-hosting or installation documentation. This has been repeatedly requested by community members interested in deploying their own instance.

Community requests

• thisiszeev (Dec 2024) — asked about Docker compose deployment
• Th3raid0r/tucson.social (Jul 2025) — interested in running their own instance
• Others in Discord #general channel

What to document

A guide covering:

1. Prerequisites — Docker, Node.js version, PostgreSQL, Redis, etc.
2. Docker Compose setup — docker-compose.yml for all services (API, PDS, database, Redis, RabbitMQ)
3. Environment configuration — required env vars, secrets, OAuth setup
4. Database setup — running initial migrations
5. AT Protocol / PDS setup — optional PDS hosting for user identities
6. Frontend deployment — building and serving openmeet-platform

Notes

• The development docker-compose-dev.yml in this repo is a starting point but is oriented toward development, not production deployment
• A production-oriented compose file or deployment guide would be the most valuable contribution
• Helm charts or Kubernetes manifests are nice-to-have but a Docker Compose guide is the priority

Getting started

Look at docker-compose-dev.yml and scripts/devnet-up.sh in this repo to understand the service dependencies. The platform repo (openmeet-platform) has its own simpler Docker setup.