feat(docs): add mdx-components for Nextra theme

Made-with: Cursor

apps/docs/mdx-components.tsx

@@ -0,0 +1,11 @@
+import { useMDXComponents as getThemeComponents } from "nextra-theme-docs";
+import type { MDXComponents } from "nextra/mdx-components";
+
+const themeComponents = getThemeComponents();
+
+export function useMDXComponents(components: MDXComponents = {}): MDXComponents {
+  return {
+    ...themeComponents,
+    ...components,
+  };
+}