Update README with logging hook section and example

[sahidvelji]

          Hey @sahidvelji, could you please also add a short section to the readme that mentions the hook? Here's an example from [Java](https://github.com/open-feature/java-sdk#logging-hook). It would be nice to include a short code example too (something currently missing from the Java example).

Originally posted by @beeme1mr in #361 (comment)

[sahidvelji]

Looks like there already is a section and an example too:
https://github.com/open-feature/go-sdk?tab=readme-ov-file#logging

[beeme1mr]

Sorry, I should have checked before making my comment. Thanks!