State the plain text requirement and bring docs into compliance
Accessibility is the project's first priority, so it has to govern our own
artifacts too. Adds a Project requirements section to the README covering the
plain text rule for documents, data, results and code, and adds CLAUDE.md so
agents working in the repo follow it without being told.
Rewrites the README to comply: markdown tables replaced with nested lists,
prose wrapped at 80 columns.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>