Create Getting Started guide, Checkpoint System guide, and Workflow FAQ

New Content Creation

The documentation audit identified three missing content pieces that would significantly improve the user experience:

Getting Started Guide

Currently, a new user must read 4+ documents to get started (README → ATLASSIAN_MCP_SETUP.md → WORKFLOW_COMMANDS.md → docs/workflow/ files). A single guide should walk through: install → configure Atlassian → run your first planning cycle.

Checkpoint System Guide

Currently buried in WORKFLOW_COMMANDS.md (lines 740-812). Deserves its own standalone page since it's a cross-cutting concern used across multiple phases.

Workflow FAQ/Troubleshooting

Common questions like "Can I skip discovery?" or "What if a ticket has no implementation details?" are answered implicitly in the docs but not collected anywhere.

Context: These are best created as part of the future Astro + Starlight docs site build, not as standalone markdown files in the current repo.

Source: Documentation audit — docs/ideas/audit-workflow-docs.md Section 3