[DOC] - Improvements to Services menu in JLab

[kcpevey]

Preliminary Checks

• [X] This issue is not a question, feature request, RFC, or anything other than a bug report. Please post those things in GitHub Discussions: https://github.com/nebari-dev/nebari/discussions

Summary

Need to add docs around the services menu in JupyterLab.

Steps to Resolve this Issue

Should be added to https://www.nebari.dev/docs/tutorials/login-keycloak