Add Page on Usage of Lombok

[jbee]

As far as I can see there is no section on usage of project lombok.

As a consequence IDEs will show compilation errors and might fail to run tests etcetera.

I think the WOW should have a page on lombok explaining how to get going and maybe also a list of features we use and don't use.

Personally I see lombok as a short term again and long term loss so I hope we use it within reason and keep it that way. Some words here in WOW might help with that too?

[jbee]

Page does actually exist: https://github.com/dhis2/wow-backend/blob/master/guides/lombok.md