feat: add ncert-neet-pdf-rewrite skill

Summary

Adds a skill that converts any NCERT Biology chapter into a NEET-exam-focused, print-ready A4 PDF using Python + ReportLab.

What this skill does

• Zero information loss rewrite — not a summary or condensation; every definition, number, scientist, qualifier word, table row, and figure caption is preserved
• Full PDF design spec — canonical ReportLab STYLES block, grey-banner headings, alternating-row tables, NOTE/MEMORY AID boxes
• Rigorous pre-writing inventory process — 3-pass source reading before a single line of script is written
• Parallel verification pass — subagents cross-check every inventory row against the generated script
• Two deliverables always — the PDF and the .py script that generated it, so any future fix is a targeted block edit, not a rewrite from scratch

Files added

• skills/ncert-neet-pdf-rewrite/SKILL.md — operational checklist and usage guide
• skills/ncert-neet-pdf-rewrite/references/master-prompt.md — full authoritative spec (content rules, PDF design, ReportLab constraints, verification procedure)

Use case

Primarily used by students and educators preparing for the Indian NEET Biology exam who want exam-optimised rewrites of NCERT chapters.