docs: add Sourcey-generated llms context

[6pt6brty57-star]

Summary

• add a reproducible Sourcey configuration over eight maintained runx documentation pages
• publish the generated static documentation graph, including llms.txt and llms-full.txt
• provide agent-readable links for getting started, skills, publishing, testing, and reference material

Why

An llms.txt gives coding agents a compact, curated map of the repository documentation while keeping the source Markdown authoritative. The checked-in config makes regeneration deterministic and reviewable.

Verification

Generated from upstream commit da74ceef021159fdb9d2d4929710bf85274d8db2 with Sourcey 3.6.5:

sourcey build --config sourcey.config.ts --output sourcey-docs

Build result: 8 pages generated successfully. I also spot-checked the getting started, agent skills, operator skills, publishing, testing, and reference entries against their source files.

This contribution was prepared for Frantic bounty #115.