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>

eslint.config.js

@@ -20,7 +20,7 @@ export default [
 		}
 	},
 	{
-		files: ['**/*.svelte'],
+		files: ['**/*.svelte', '**/*.svelte.ts'],
 		languageOptions: {
 			parserOptions: {
 				parser: ts.parser