Fix formatting of lint rule descriptions in index (#7150)

These descriptions are expected to be wrapped in a `<p>` and can
actually contain separated paragraphs occasionally, so they shouldn't be
parsed as inline markdown.

Fixes #7138

Author: parlough

site/lib/src/pages/lint_index.dart

@@ -79,7 +79,7 @@ class _LintRuleCard extends StatelessComponent {
       ],
       content: [
         if (lint.description.isNotEmpty)
-          DashMarkdown(content: lint.description, inline: true),
+          DashMarkdown(content: lint.description),
       ],
       actions: CardActions(
         leading: _statusIcons,