docs: add missing skills to README

[SparshM8]

Summary

Update README.md to document five skills (session-to-skill, recall, replay, teach, address-findings) that exist in the skills/ directory but were omitted from the README's "Included skills" section and "What skills help agents do" table.

Skill	Path	Summary
session-to-skill	skills/session-to-skill/SKILL.md	Extracts reusable workflow patterns from session history or checkpoints to generate a skill draft
recall	skills/recall/SKILL.md	Searches prior sessions for similar work and builds a task playbook
replay	skills/replay/SKILL.md	Sequences checkpoints chronologically to walk through how a feature was built step by step
teach	skills/teach/SKILL.md	Synthesizes a guided lesson with system overview and key takeaways from canonical checkpoints
address-findings	skills/address-findings/SKILL.md	Fetches open review findings from an Entire trail and applies fixes in the local worktree

Skill changed

• No skill changed
• New skill
• Existing skill:

Validation

• npx -y skills@latest add . --list --yes
• JSON metadata validated, if changed
• OpenCode plugin syntax checked, if changed
• Markdown previewed, if changed

Example prompt

N/A — Documentation update adding 5 missing skills to README.md.