fix: migrate onBrokenMarkdownLinks to new config path

- Move from deprecated siteConfig.onBrokenMarkdownLinks
- To siteConfig.markdown.hooks.onBrokenMarkdownLinks
- Fixes Docusaurus v3 deprecation warning

Author: darianstlex

docs-site/docusaurus.config.ts

@@ -14,7 +14,12 @@ const config: Config = {
   deploymentBranch: 'gh-pages',
 
   onBrokenLinks: 'warn',
-  onBrokenMarkdownLinks: 'warn',
+
+  markdown: {
+    hooks: {
+      onBrokenMarkdownLinks: 'warn',
+    },
+  },
 
   i18n: {
     defaultLocale: 'en',