V0.9

Add LLM instructions and Claude Code skill for driving BrowserHost

- docs/llm-instructions.md: tool-agnostic guide for any LLM/agent, with a
  worked BBC News example
- .claude/skills/browser-via-browserhost: ready-made Claude Code skill that
  remembers the host in a git-ignored host.txt
- README: prominent links to both
- .gitignore: exclude the skill's local host.txt

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>