Add next config type checking

Author: shellbear

next.config.js

@@ -1,3 +1,8 @@
+// @ts-check
+
+/**
+ * @type {import('next').NextConfig}
+ **/
 module.exports = {
   images: {
     domains: ['rdl.ink'],
@@ -6,7 +11,6 @@ module.exports = {
     if (!isServer) {
       config.resolve.fallback.fs = false;
     }
-
     config.module.rules.push({
       test: /\.md|\.mdx$/,
       use: 'raw-loader',