Add human-focused README.md to every skill and bundle directory

Each README is written for a human audience, explaining:
- What the skill does (not what format it follows)
- What benefit the user gets from installing it
- Quick setup and usage patterns
- When to load/trigger the skill
- What scripts, references, and templates it ships

data-scientist already had a README — left unchanged.

48 READMEs added across all skill and bundle directories.

hugo-theme/README.md

@@ -0,0 +1,30 @@
+# Hugo Theme Development
+
+Intermediate-to-advanced patterns for building and customizing Hugo CMS themes. Covers template architecture, asset pipeline, shortcodes, performance, SEO, and accessibility.
+
+## Why Install This Skill
+
+When your agent loads this skill, it becomes a **Hugo theme developer** who can:
+
+- **Set up template architecture** — baseof.html with blocks, template lookup order, partials
+- **Integrate Tailwind CSS** — v4 with `css.TailwindCSS` or v3 with PostCSS
+- **Build responsive images** — srcset, Hugo Pipes processing
+- **Create shortcodes and render hooks** — complex nested shortcodes, Mermaid, custom link/image rendering
+- **Optimize performance** — partialCached, cache TTLs, build speed
+- **Implement accessibility** — semantic HTML landmarks, ARIA patterns, keyboard navigation
+- **Configure SEO** — JSON-LD structured data, Open Graph, Twitter Cards
+
+## What You Get
+
+| Directory | Purpose |
+|-----------|---------|
+| `SKILL.md` | Quick-start theme bootstrap, reference file index |
+| `references/` | 7 reference files: template architecture, asset pipeline, shortcodes & hooks, content & i18n, modules & performance, design & accessibility, SEO & output formats |
+
+## Triggers
+
+Load this when working on a Hugo theme or site template layer.
+
+## Requirements
+
+Hugo v0.154+. Works with any agent framework supporting the Agent Skills format.