[site,#572][xs]: remove components/prose.js as no longer used.

site/components/prose.js

@@ -1,13 +0,0 @@
-export default function Prose({
-  children,
-  mdFile=null
-}) {
-  return (
-    <main className="prose mx-auto my-24">
-      {mdFile &&
-        <div dangerouslySetInnerHTML={{ __html: mdFile }} />
-      }
-      {children}
-    </main>
-  )
-}