remove modal from sidebar (fragment doesn't exist)

apps/design-system/config/docs.ts

@@ -127,11 +127,6 @@ export const docsConfig: DocsConfig = {
           href: '/docs/fragments/empty-state-presentational',
           items: [],
         },
-        {
-          title: 'Modal',
-          href: '/docs/fragments/modal',
-          items: [],
-        },
         {
           title: 'Page Container',
           href: '/docs/fragments/page-container',