Feat: Autogenerated config sample from config golang struct

[deryrahman]

Is your feature request related to a problem? Please describe.
Sometimes whenever the changes in the structure of optimus configuration (./config/config.go) happens, contributors are sometimes usually forget to update the docs.

To get a better maintainability and consistency, we should rely on the code as a single source of truth. Hence, docs should be updated the sample config automatically whenever the config's structure in the source code is changed.

Describe the solution you'd like
Using 3rd party library. I haven't found yet the golang lib that suitable for this purpose. But, there's a library (gojson) which can convert sample yaml to golang struct. What we need is the inverse version of gojson.

Describe alternatives you've considered
Adding new lib to convert from golang struct to sample config yaml. Introduce this lib on odpf ecosystem through odpf/salt

Additional context
N/A