feat: add showcase deck and enhance demo slides

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

decks/showcase/slides.md

@@ -0,0 +1,130 @@
+---
+theme: default
+title: Slidev Showcase
+transition: slide-left
+mdc: true
+---
+
+# Slidev Showcase
+
+Explore the powerful features of Slidev
+
+<div class="abs-br m-6 text-sm opacity-50">
+  Press <kbd>Space</kbd> to navigate
+</div>
+
+---
+layout: center
+---
+
+# Click Animations
+
+<v-clicks>
+
+- Elements appear one by one
+- Supports nested lists
+- Great for step-by-step explanations
+
+</v-clicks>
+
+---
+
+# Two-Column Layout
+
+::left::
+
+### Features
+
+<v-clicks>
+
+- Markdown-based
+- Vue components
+- Code highlighting
+- Diagrams & Math
+
+</v-clicks>
+
+::right::
+
+<v-click>
+
+```ts
+// It's just Markdown!
+interface Slide {
+  content: string
+  layout?: string
+  transition?: string
+}
+```
+
+</v-click>
+
+---
+
+# Code Highlighting
+
+```ts {2-3|5-7|all}
+function fibonacci(n: number): number {
+  if (n <= 1) return n
+  return fibonacci(n - 1) + fibonacci(n - 2)
+}
+
+// Click through to reveal lines
+const result = fibonacci(10)
+console.log(`fib(10) = ${result}`)
+```
+
+<br>
+
+<v-click>
+
+> Use `|` separator to highlight lines per click
+
+</v-click>
+
+---
+
+# Mermaid Diagrams
+
+```mermaid
+graph LR
+    A[Markdown] --> B[Slidev]
+    B --> C[Vite]
+    B --> D[Vue]
+    C --> E[SPA]
+    D --> E
+    E --> F[Deploy]
+```
+
+---
+
+# Math Equations
+
+Inline math: $E = mc^2$
+
+Block math:
+
+$$
+\int_{-\infty}^{\infty} e^{-x^2} dx = \sqrt{\pi}
+$$
+
+<br>
+
+<v-click>
+
+Powered by **KaTeX** — fast and beautiful math rendering
+
+</v-click>
+
+---
+layout: center
+class: text-center
+---
+
+# That's Slidev
+
+Write slides in Markdown, present with style.
+
+<div class="mt-8 text-sm opacity-60">
+  <a href="https://sli.dev" target="_blank">sli.dev</a>
+</div>