docs: missing information on how to configure logger casing through atributes

[t1agob]

What were you initially searching for in the docs?
How to define logger output casing with attributes.

Is this related to an existing part of the documentation? Please share a link
https://sturdy-umbrella-97433f53.pages.github.io/core/logging/#configure-log-output-casing

Describe how we could make it clearer
Explain how to set the logger output casing through attributes and not only environment variables.

If you have a proposed update, please share it here
Update documentation by adding an example.