feat(seo, routing): add Bisaya learning and German for Bisaya courses

- Introduced new routes for Bisaya learning and German for Bisaya courses, enhancing the marketing section of the application.
- Updated sitemap.xml to include new course URLs for better SEO visibility.
- Added localization entries for both courses in English and German, improving content accessibility for users.
- Enhanced SEO metadata generation for the new courses, ensuring proper indexing and visibility in search engines.
- Updated VocabLandingView to feature links to the new courses, improving user navigation and engagement.

frontend/src/utils/seo.js

@@ -219,6 +219,42 @@ export function buildRouteJsonLd(route, t, uiLocale) {
     ];
   }
 
+  if (name === 'BisayaLearningLanding') {
+    return [
+      {
+        '@context': 'https://schema.org',
+        '@type': 'Course',
+        name: t('seo.bisayaLearning.jsonLdName'),
+        url: buildAbsoluteUrl('/bisaya-lernen'),
+        description: t('seo.bisayaLearning.jsonLdDescription'),
+        inLanguage: lang,
+        provider: {
+          '@type': 'Organization',
+          name: DEFAULT_SITE_NAME,
+          sameAs: buildAbsoluteUrl('/'),
+        },
+      },
+    ];
+  }
+
+  if (name === 'GermanForBisayaLanding') {
+    return [
+      {
+        '@context': 'https://schema.org',
+        '@type': 'Course',
+        name: t('seo.germanForBisaya.jsonLdName'),
+        url: buildAbsoluteUrl('/deutsch-fuer-bisaya'),
+        description: t('seo.germanForBisaya.jsonLdDescription'),
+        inLanguage: lang,
+        provider: {
+          '@type': 'Organization',
+          name: DEFAULT_SITE_NAME,
+          sameAs: buildAbsoluteUrl('/'),
+        },
+      },
+    ];
+  }
+
   if (name === 'BlogList') {
     return [
       {