[DOC] - Create placeholder docs setup

[andrewfulton9]

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

Add placeholder docs and framework for building and deploying:

• github workflow that builds in pr and deploys to gh pages on merge to main
• astro/typescript/npm configs
• readme.md on tools, how to build, serve ect
• docs/introduction page
• relevant styling assets
• update .gitignore

[viniciusdc]

Parking a content item here for whenever the Astro/Starlight scaffold lands (the astro/typescript/npm configs box above).

The enterprise CA bundle / TLS-inspecting egress feature (shipped in #102, closed #85) has no user-facing docs. Right now it only lives as inline comments in values.yaml:

https://github.com/nebari-dev/nebari-data-science-pack/blob/main/values.yaml

It's gated behind custom.trust-bundle-enabled and defaults to false, so it's easy to miss that it exists at all. That's actually what led to #154 getting filed as a fresh request when the feature was already there. A short page covering when to turn it on, the config keys, and how the init-container merge lines up with NIC core's trust-manager would close that gap.

Not urgent, just don't want it to fall through once we have somewhere to put it. Holding off on writing it until the site framework is settled so we're not authoring against Hugo.