Update Documentation

See merge request !4

First working version that retrieves the real state from the device

See merge request !2

Update CI to build binary packages and create releases on tag pipelines

See merge request !3

- update log messages

expanded README with code structure and implemented Os_client interface in freebsd os client - untested!

extended ygot struct with network-instance yang model and its dependencies. also changed the go:generate to also create setter/getter/annotations etc.

refactor and unified ygot struct

See merge request !1

- add Dockerfile
- add .gitlab-ci.yml

refactored server to use oc_interface, not ygotstructs, and removed ygotstructs. also added osclient flag to start command (currently unused)

added original oc-freebsd-target ygot struct (actually calling the freebsd client not yet implemented)

incomplete first develop branch: merged my parts of oc-freebsd-target with my work and created structure