Production-ready server deployment notes

[tomasMizera]

Let's add a section to custom hosting how to host the server on production

• add SSL
• Nginx config(?) - secure cookies
• SMTP setup

[MarcelGeo]

Here is link for production nginx configuration which is ready to edit by administrators. It contains also security enhancements. It's result of previous deployments by @varmar05 . https://github.com/MerginMaps/server/blob/master/ssl-proxy.conf

[varmar05]

it would be also good to have some high level architecture diagram so admins understand the use of stack components

[fernandinand]

Partially covered on #556