add language learner project

Dutch and Korean (explained in English) and English (explained in Dutch)
from A1 to C1, with a Hangul level for Korean. Lessons with notes, words
and sentences generate multiple-choice, typing, sentence building, cloze,
listening and matching exercises. Endless challenges: a seeded daily
challenge, sprint, survival, mixed practice, level tests, spaced-repetition
reviews and generated drills (numbers, clock times, de/het, plurals, Dutch
and Korean conjugation, particles, Hangul reading, irregular verbs).
Progress is stored in localStorage with export/import.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/lib/projects.ts

@@ -35,6 +35,12 @@ export const projects = [
 		href: '/projects/world-opinions',
 		external: false
 	},
+	{
+		name: 'language learner',
+		subtitle: 'Dutch, Korean and English, from zero to fluent',
+		href: '/projects/language-learner',
+		external: false
+	},
 	{
 		name: 'money tracker',
 		subtitle: 'a manual ledger for accounts, bills and utilities',