Document typical deployment cases

[yamalight]

trafficstars

There's currently a few typical use cases for exoframe - would be great to have those as step-by-step guides in docs. Cases (to be extended):

• [ ] Basic project deployment with custom domain, env vars
• [ ] Deploying project to path instead of just domain name
• [ ] Deploying project that has db + service:
  • [ ] Basic deployment with compose (write down downsides)
  • [ ] "Optimal" deployment as two exoframe deployments (db as a separate thing via image field)