Make docker-compose more clear and explicit (#2469)

Make docker-compose more clear and explicit (#2469)

* Make docker-compose more clear, starting with dev

Explicit networks, not opining ports when not necessary: Confusing for users. All requests go through nginx, so there is no need to open ports directly on pictrs and other services for example. I wasn't sure about jaeger and otel, maybe that can be changed somewhat too.

Also adding comments and things that are relevant for a prod setup too.

* Update with comments

* Providing dedicated nginx and lemmy conf

* Fix config key for pictrs.

* Fix config key for pictrs.

* updates on naming

* Adding docker compose build info

* Revert to more complete lemmy config

* Test and fix build paths

* Fix otel config

* Delete dev file

Co-authored-by: Dessalines <dessalines@users.noreply.github.com>