Read/Write database selection

[devon2018]

Is your feature request related to a problem? Please describe.
I need to implement read and write replicas of my database in my app, I know I can pass the db to the model query directly using use_db.

Describe the solution you'd like
It would be great if when creating my OrmarConfig I could define a read only database that will get used for all read operations and the default database will be used for write, what would be even better.

Describe alternatives you've considered
using the use_db function but seems a bit messy, this is a config that a lot of other frameworks provide so would be good to consider for a future release.

Additional context
Not that I can think of.