fix: generated index URLs were URI encoded (#32226)

Signed-off-by: aramissennyeydd <aramis.sennyey@doordash.com>

microsite/sidebars.ts

@@ -27,17 +27,17 @@ function sidebarElementWithIndex(
   },
   children: Array<string | object>,
 ) {
-  const { label, description, differentiator } = element;
+  const { label, description, differentiator = '' } = element;
   return {
     type: 'category',
-    label: label,
+    label,
     description,
     link: {
       type: 'generated-index',
       title: label,
       slug: `/${differentiator}${label
         .toLowerCase()
-        .replace(/[^a-z0-9 _-]/gi, '-')}/generated-index`,
+        .replace(/[^a-z0-9]/g, '-')}/generated-index`,
     },
     items: children,
   };