[DOC] - Update usage of nebari's docker-images and how to extend it

[viniciusdc]

Preliminary Checks

• 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

We need to expand our docs on how to use our docs images and expanding their functionalities.

Steps to Resolve this Issue

1. Update outdated information first
2. Expand docs on how to use our images and customize
   ...