Test for both md and mdx

apps/temp-docs/lib/docs.ts

@@ -5,9 +5,24 @@ import matter from 'gray-matter'
 const docsDirectory = process.cwd()
 
 export function getDocsBySlug(slug: string) {
+  console.log('getDocsBySlug', { slug })
   const realSlug = slug.replace(/\.mdx$/, '')
-  let fullPath = join(docsDirectory, `${realSlug}.mdx`)
 
+  // files can either be .md or .mdx
+  // we need to check which one exists
+  let fullPath
+  let fullPathMD = join(docsDirectory, `${realSlug}.md`)
+  let fullPathMDX = join(docsDirectory, `${realSlug}.mdx`)
+
+  if (fs.existsSync(fullPathMD)) {
+    fullPath = fullPathMD
+  }
+
+  if (fs.existsSync(fullPathMDX)) {
+    fullPath = fullPathMDX
+  }
+
+  // if no match, 404
   if (!fs.existsSync(fullPath)) {
     console.log(`\nfile ${fullPath} not found, redirect to 404\n`)
     fullPath = join(docsDirectory, 'docs/404.mdx')