[DOC] - Updates docs for Nebari-Slurm (previously Nebari-HPC)

[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

This is a WIP issue to migrate Nebari-slurm docs into nebari's

Steps to Resolve this Issue

1. Evaluate current Nebari-Slurm docs
2. Migrate docs into new section
3. Formate documentation layout to accommodate both projects
   ...

[pavithraes]

Docs were migrated in #535, they still need to be reviewed and updated.