docs: add foundation documentation structure

[shiv-tyagi]

Summary

Replace the monolithic docs/quickstart.md with a structured documentation set covering the essential paths for users and contributors.

Structure

docs/
├── index.rst                  (top-level toctree)
├── getting-started.rst        (single-node quickstart)
├── deployment/
│   ├── index.rst
│   ├── bare-metal.rst         (WireGuard mesh, config, HA, job env vars)
│   └── kubernetes.rst         (images, manifests, operator, SpurJob CRD)
└── developer/
    ├── index.rst
    ├── building.rst           (prerequisites, build, unit + E2E tests)
    └── contributing.rst       (fork workflow, commit style, hooks, PR process)

Changes

• README.md — trimmed to elevator pitch + signposts; all links verified against new structure
• Quickstart — install, start controller/agent, submit a job, Slurm compat (subcommands + symlinks)
• Bare-metal deployment — install, controller setup (config, systemd, HA), worker join, env vars, GPU isolation
• Kubernetes deployment — image build, component descriptions, manifest apply order, ConfigMap, SpurJob CRD, verification
• Building guide — prerequisites, build, unit tests, full E2E instructions for both bare-metal and K8s (env vars, node setup, AppArmor, RBAC, cleanup)
• Contributing guide — fork + upstream workflow, conventional commits, license headers, pre-commit hooks, PR and review process
• crates/spur-tests/README.md — short pointer to the building guide E2E sections
• Deleted old docs/quickstart.md

[Copilot]

Pull request overview

This PR restructures Spur’s documentation by replacing the old monolithic docs/quickstart.md with a Sphinx/ReST-style doc tree (getting started, deployment, developer guides) and updating top-level entry points to link into the new structure.

Changes:

• Replace docs/quickstart.md with a new docs/index.rst + sectioned guides under docs/deployment/ and docs/developer/.
• Update README.md to be a short overview with install/run snippets and pointers into the new docs.
• Add a short crates/spur-tests/README.md that points contributors to the E2E instructions in the developer docs.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
README.md	Replaces long-form README content with highlights, install, and doc signposts.
docs/quickstart.md	Removes the old markdown quickstart guide.
docs/index.rst	Adds a top-level docs landing page and toctree.
docs/getting-started.rst	Adds a concise single-node quickstart and Slurm-compat usage examples.
docs/deployment/index.rst	Adds deployment section toctree.
docs/deployment/bare-metal.rst	Adds bare-metal install/controller/HA/worker join guidance.
docs/deployment/kubernetes.rst	Adds Kubernetes deployment guide and SpurJob CRD example.
docs/developer/index.rst	Adds developer section toctree.
docs/developer/building.rst	Adds build + unit and E2E test instructions (bare-metal and Kubernetes).
docs/developer/contributing.rst	Adds contribution workflow, commit style, hooks, and PR process.
crates/spur-tests/README.md	Adds a pointer from the test crate to the developer E2E docs.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.