feat: add initial Slidev presentation and demo components

- Created Slidev presentation structure with index.md and contents.md.
- Implemented footer and menu components for navigation.
- Added Markdown preview component with syntax highlighting.
- Developed HTML template for consistent page structure.
- Introduced button component with variant support.
- Added Vue counter component for interactive demos.
- Configured content collections for documentation.
- Created multiple markdown documents for demo purposes.
- Established global and theme styles for consistent UI.
- Set up TypeScript configuration for better development experience.

solution/kevisual.json

@@ -0,0 +1,25 @@
+{
+  "metadata": {
+    "name": "kevisual",
+    "share": "public"
+  },
+  "registry": "https://kevisual.cn/root/ai/kevisual/frontend/simple-astro-template",
+  "clone": {
+    ".": {
+      "enabled": true
+    }
+  },
+  "syncd": [
+    {
+      "files": [
+        "**/*"
+      ],
+      "registry": ""
+    }
+  ],
+  "sync": {
+    ".gitignore": {
+      "url": "/gitignore.txt"
+    }
+  }
+}