Is your feature request related to a problem? Please describe.
We're running self-hosted r2r in production and we'd like to have logs. Ideally in our own logging system (datadog) together with logs for all other components of our system.

Describe the solution you'd like
I could contribute a PR that adds optional datadog LLM Observability support to R2R, and so every user that uses datadog would be happy. This would involve adding a file that based on config either imports datadog or defines functions with the datadog API signatures that do nothing, and using those functions everywhere in the code where it makes sense.

Describe alternatives you've considered
If that's too much dirtying of the code, I'm also fine with contributing a few config values for changing litellm log configuration: litellm logging level as well as a custom logging function that logs the raw request and response with the INFO level.

Additional context
Also, you should really consider updating your docs (for both R2R and R2R-Application) to reflect that you don't support the logging API and dashboard anymore, since I just spent two hours digging through your code until I finally found that it was removed in v3.4.5 (and replaced with victoria-logs, which seems to have been also removed at some point?).