misc/dl: add note about original solution

docs/pages/misc/dl.html

@@ -12,4 +12,11 @@ <h2>
     <img src="{{assets}}victorz/dl/i/upload.png" alt="upstream">
 </h2>
 
+<p class="my-3 small">
+    While this is now a custom-built solution,
+    the downloads section of my website originally used
+    Evoluted's <a href="https://www.evoluted.net/blog/development/php-directory-listing-script" rel="nofollow">PHP Directory Listing Script</a> v3, and
+    later on, it became a modified version of that script.
+</p>
+
 {%- include 'app.html' -%}