Simplify Humanizer packaging and README

[blader]

What changed

• lead the README with what Humanizer does and how its rewrite loop works
• move a shorter installation section to the bottom and collapse release history
• keep one regular root SKILL.md and point the Claude plugin at it
• remove the symlink, the separate Claude Desktop ZIP builder, and its release workflow
• sync the package descriptions and bump the package to v2.11.2

Why

The README made readers work through installation details before explaining the skill. The package also carried two layouts for one prompt: a root skill for Agent Skills tools and a symlink under skills/ for the Claude plugin. That symlink made GitHub's source ZIP unusable in Claude Desktop and required a second release artifact.

Current Claude Code can load the root skill through the plugin manifest. Using that path leaves one skill authority, keeps /humanizer:humanizer, and gives Claude Desktop a source ZIP with one regular SKILL.md and no symlinks.

The 35 writing patterns and their behavior are unchanged.

Validation

• git diff --check
• python3 scripts/validate-package.py
• python3 skill-creator/scripts/quick_validate.py .
• npx --yes skills@1.5.20 add . --list
• claude plugin validate --strict .
• claude plugin validate --strict .claude-plugin/plugin.json
• runtime resolution of /humanizer:humanizer with the root-only plugin layout