Make nextra compatible with stackblitz

Author: pomber

examples/nextra/next.config.js

@@ -0,0 +1,12 @@
+const { remarkCodeHike } = require("@code-hike/mdx")
+const theme = require("shiki/themes/material-palenight.json")
+
+const withNextra = require("nextra")({
+  theme: "nextra-theme-docs",
+  themeConfig: "./theme.config.mjs",
+  mdxOptions: {
+    remarkPlugins: [[remarkCodeHike, { theme }]],
+  },
+})
+
+module.exports = withNextra()