feat: initialize Hugo static site with Bootstrap 5.x

Initialize minimal Hugo site structure with Bootstrap 5.3.2 integration for
markusgraf.ch conversion. Implements OpenSpec proposal add-minimal-hugo-site.

Features:
- Hugo project structure with standard directories
- Base layout template (baseof.html) with Bootstrap 5.3.2 via CDN
- Homepage (index.html) and single page (single.html) templates
- Reusable partials: header, footer, navigation
- Responsive Bootstrap grid layout
- Mobile-first design with semantic HTML5
- Valid HTML output with basic accessibility features
- Taxonomies disabled for minimal site (see docs/TAXONOMIES.md)

Documentation:
- IMPLEMENTATION_SUMMARY.md - Complete implementation guide
- docs/TAXONOMIES.md - Guide for re-enabling categories/tags
- static/README.md - Guide for placing static assets

Configuration:
- hugo.toml configured for markusgraf.ch
- .gitignore for Hugo build artifacts

All 24 tasks from OpenSpec proposal completed successfully.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

layouts/_default/single.html

@@ -0,0 +1,21 @@
+{{ define "main" }}
+<div class="container">
+  <div class="row">
+    <div class="col-lg-8 offset-lg-2">
+      <article class="mt-5 mb-5">
+        <header class="mb-4">
+          <h1 class="display-5">{{ .Title }}</h1>
+          {{ if .Date }}
+          <p class="text-muted">
+            <time datetime="{{ .Date.Format "2006-01-02" }}">{{ .Date.Format "January 2, 2006" }}</time>
+          </p>
+          {{ end }}
+        </header>
+        <div class="content">
+          {{ .Content }}
+        </div>
+      </article>
+    </div>
+  </div>
+</div>
+{{ end }}