docs: Actualizar REFERENCE.md con fuente embebida

- Cambiar ejemplo TTF a usar initEmbedded() (recomendado)
- Añadir nota sobre fuente embebida en Features

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

REFERENCE.md

@@ -652,10 +652,13 @@ TTF fonts are fully supported with real glyph rasterization and antialiasing.
 const TtfFont = zcatgui.render.TtfFont;
 const FontRef = zcatgui.render.FontRef;
 
-// Load TTF from file
-var ttf = try TtfFont.loadFromFile(allocator, "/usr/share/fonts/adwaita-sans-fonts/AdwaitaSans-Regular.ttf");
+// RECOMMENDED: Use embedded font (zero dependencies)
+var ttf = try TtfFont.initEmbedded(allocator);
 defer ttf.deinit();
 
+// Alternative: Load TTF from file
+// var ttf = try TtfFont.loadFromFile(allocator, "/path/to/font.ttf");
+
 // Set render size (glyphs cached per size)
 ttf.setSize(14);  // 14pt
 
@@ -675,6 +678,7 @@ font_ref.drawText(&framebuffer, x, y, "Hello", color, clip);
 ```
 
 **Features:**
+- **Embedded font**: AdwaitaSans-Regular included (~860KB), zero external dependencies
 - Real bezier curve rasterization (quadratic beziers)
 - Antialiasing via 2x supersampling
 - Glyph caching (by codepoint + size)